Why so little overclocking?

[Loa]

Hello,

It seems that everytime I visit a tech site like anandtech and stumble on CPU articles or discussions, they talk about overclocking. On the latest i3 CPU, the author overclocked the 2.93GHz to a stable 4GHz wihtout even needing additional cooling.

Why is overclocking such a big deal on the PC side, but not on the Mac side even though we're using the same family of chips?

Thanks

Loa

[Eidorian]

Apple's control over its EFI firmware puts a damper on having fun with BLCK speeds and memory timings.

[aliot]

OC on a mac pro?Why?For what?

[Cindori]

For what? Well of course more performance.


but as Eidorian said, we don't have BIOS, so no easy overclocking.

Overclocking the octo 2.26 GHz to 2.93 GHz would save you $ 2,600, and I'm pretty sure the Xeons would handle it well.

[alphaod]

Stability is also more important than sheer performance; at least that's how we're suppose to see it; Macs are for serious folks. :p

[Ca$hflow]

I think they should allow macs to be over clocked. They should do it in a way that if someone does then the warrantee is null and void.

[Gomff]

I can't ever see Apple sanctioning overclocking their machines and potentially allowing the user to damage or at least make them less stable.....They'd be too worried about the harm to their reputation.

Overclocking is one of those things that highlights the cultural difference between PC and Mac ownership.

[TheSpaz]

ZDNet Overclocking Tool:

http://www.zdnet.de/einsatz_von_apple_macintosh_in_unternehmen_exclusive_zdnet_overclocking_tool_enhances_performance_of _mac_pro_story-39002307-39192217-1.htm

[300D]

Spend $4,000 on a machine and then tell us about how fast you got the CPU's and how much they cost to replace with a void warranty.

[Eidorian]

Spend $4,000 on a machine and then tell us about how fast you got the CPU's and how much they cost to replace with a void warranty.Some people do that...

I'm more fond of $100-200 processors on air though.

[aliot]

For what? Well of course more performance.


but as Eidorian said, we don't have BIOS, so no easy overclocking.

Overclocking the octo 2.26 GHz to 2.93 GHz would save you $ 2,600, and I'm pretty sure the Xeons would handle it well.

Are you serious?How much you can got form 2.26 to 2.93?Don't forget you can't change a bigger fan or liquid cooling in a mac pro,at least not on a easy way.
If you using a E5200 OC will help, because it worth a try and E5200 really just a eco choice.On a powerful dual xeon system...maybe not so much.

[dukebound85]

Are you serious?How much you can got form 2.26 to 2.93?Don't forget you can't change a bigger fan or liquid cooling in a mac pro,at least not on a easy way.
If you using a E5200 OC will help, because it worth a try and E5200 really just a eco choice.On a powerful dual xeon system...maybe not so much.

I have oc'd a q6600 from 2.4 to 3ghz with no issues and not changing any voltages or components

[Gomff]

ZDNet Overclocking Tool:

http://www.zdnet.de/einsatz_von_apple_macintosh_in_unternehmen_exclusive_zdnet_overclocking_tool_enhances_performance_of _mac_pro_story-39002307-39192217-1.htm

Hmmm. Not sure if this is the same thing as "real" overclocking PC style, or a good idea :eek:

Nudging the slider up just a fraction basically causes an instant Kernel Panic on my 2008, 2.8 Ghz Octo.

Note to self: My machine is plenty fast enough, even for 3D rendering that uses all 8 cores.

[Loa]

Hahaha,

Thanks for the EFI-BIOS replies!

For the rest... funny replies! Sounds like GM employees defending their company's bad decisions.

Judging from *most* of the replies, we don't have OC on Macs because most ppl are:

-afraid
-prejudiced
-using knowledge that is decades old

Read up on what's possible on simple i3 chips today. Going from 2.93 to 4. Without using extra cooling. With stability.

If i3 chips can do that, what can the workstation grade CPUs in our MPs do?

I'm aghast at the tone of most replies!

Loa

[Transporteur]

Read up on what's possible on simple i3 chips today. Going from 2.93 to 4. Without using extra cooling. With stability.


Yes, but for how long?
Please read up on electromigration!

A MacPro is a workstation (or at least tries to be one :D). That requires stability in all points for a long time.
In fact overclocking with that high rates WITHOUT proper cooling can destroy your CPU in just a couple of month.
I once pushed it to high myself. 3.2 to 4.4GHz. Even with a decent watercooling (core temps never higher than about 50° C), the CPU died after only three month. It started with not reaching the clock speed of 4.4, and finished with not even reaching 2GHz.
That's definitely not what you want in a 3000$ machine that, in case of the most companies, has to last at least 3 years.

Moderate overclocking is no big deal but I don't think Apple will ever make this possible.

[Umbongo]

No Intel partner offers Nehalem based Intel Xeon workstations with overclocking capability. No dual socket board supports processor clock speed overclocking. It isn't Apple's decision. You can overclock Xeons and get similar gains to the Core i7s using an X58 board so we could have 4GHz Mac Pros, Intel just choose to not allow it at a commercial level.

[lemonade-maker]

Overclocking gives marginal gains compared to potential failure. It really is not req'd on a mac. There other methods of improvement that will give real world benifits and won't compromise longevity (raid0, ssd, memory). If you make a living on the machine and it's too slow, buy a faster machine. If you bought a mac to OC, you made a mistake.

[TennisandMusic]

Overclocking gives marginal gains compared to potential failure. It really is not req'd on a mac. There other methods of improvement that will give real world benifits and won't compromise longevity (raid0, ssd, memory). If you make a living on the machine and it's too slow, buy a faster machine. If you bought a mac to OC, you made a mistake.

Man you have no idea what you're talking about. You can EASILY overclock i7 920's with no worry about "potential failure" or "marginal gains." You can take the 2.66ghz cpu up to 4 ghz on air! Come on now, please don't make things up just to try and assuage the Apple fans. I'm not saying the Mac Pros need overclocking per se, but that is just not cool.

[Eidorian]

Man you have no idea what you're talking about. You can EASILY overclock i7 920's with no worry about "potential failure" or "marginal gains." You can take the 2.66ghz cpu up to 4 ghz on air! Come on now, please don't make things up just to try and assuage the Apple fans. I'm not saying the Mac Pros need overclocking per se, but that is just not cool.3.2 GHz on stock voltages (http://www.tomshardware.com/reviews/core-i5-750-efficiency,2500.html) is pretty tame stuff.

[sushi]

One reason is that Apple wants to ensure stability of their systems.

OC'ing doesn't always create a stable system environment.

[Transporteur]

Man you have no idea what you're talking about. You can EASILY overclock i7 920's with no worry about "potential failure" or "marginal gains." You can take the 2.66ghz cpu up to 4 ghz on air!

Seems as if we've got another candidate that hasn't done his homework...

Again, read up on electromigration! If you haven't heard about it in the context of overclocking, well, sorry to say but 'you have no idea what you're talking about'.
2.66 to 4 is just pathetic with air.

[hwhalers]

Why would I threaten my warranty within the first three years? It's just not worth it. I need my computer to work correctly a lot more than I need it to work a little bit faster. After the AppleCare period I might consider it, if it wasn't better to sell it and buy a newer one.

I don't care about getting 3 or 4 more FPS in whatever the newest game is on a computer that'll break or get replaced within the year, so I don't bother overclocking.

And don't reply that I don't know anything about overclocking. I'm aware of the excess speeds that can be attained on air these days, and I'm aware that my low-binned Xeons are probably capable of faster than they're certified at. I don't actually care.

[lemonade-maker]

Man you have no idea what you're talking about. You can EASILY overclock i7 920's with no worry about "potential failure" or "marginal gains." You can take the 2.66ghz cpu up to 4 ghz on air! Come on now, please don't make things up just to try and assuage the Apple fans. I'm not saying the Mac Pros need overclocking per se, but that is just not cool.

You may be right but you are not. If you bought a mac to overclock it, you are the person who is missing out on knowledge. Buy pc and burn it up, have fun with that. Put mac os on it, if you are capable.

[pprior]

Part of the reason I bought a mac is to get AWAY from all the nonsense with overclocking.

Personally I find it tiring to hear everyone droning on and on about cooling techniques and tweaks to keep their machines from crashing.

I value stability above all. that's a big reason I switched to mac. I have 0% interest in overclocking and could care less.

[Dr.Pants]

3.2 GHz on stock voltages (http://www.tomshardware.com/reviews/core-i5-750-efficiency,2500.html) is pretty tame stuff.

:D That it is. If I wasn't a student, I swear... :o

Seems as if we've got another candidate that hasn't done his homework... Again, read up on electromigration!

Read about it on Wikipedia and have a good idea of what it does and how it works; do you have any more information specific to the matter? Something you've read, pertaining to overclocking?

[Techhie]

One reason is that Apple wants to ensure stability of their systems.

OC'ing doesn't always create a stable system environment.

Although overclocking a system built for stability is somewhat redundant, it's obvious that they don't allow it (at least on a software level, even on the GPU) because they are trying to shoehorn people into paying that $2,600 for a slightly faster chip.

[lemonade-maker]

Although overclocking a system built for stability is somewhat redundant, it's obvious that they don't allow it (at least on a software level, even on the GPU) because they are trying to shoehorn people into paying that $2,600 for a slightly faster chip.

And jfk was a cover up and the moon mission was a studio in Hollywood.

[Cindori]

Intel is about to release the 930 desktop chip.


This is EXACTLY the same chip as the 920, but it's factory overclocked to 3GHz from 2.66.

My point is that every CPU has headroom for moderate OC without losing stability. Intel wouldnt sell an unstable CPU, right?

[aliot]

I saw guys compare xeon with the desktop chips.DO you guys really know why xeon's are so expensive?I assume everybody know that chips have different quality the best will be the highest feq cpu the the second grade will be the slower one.xeon 2.93 almost 6-8 times more expensive than 2.0 .
why?because every grade of xeon have only a little bit space to "OC".Intel is not a fool. if the chips can work on a higher feq they will belong to the next grade.;)use the desktop chip's idea on server chips...umm rethink?

[hwhalers]

Intel wouldnt sell an unstable CPU, right?

I'm (http://www.tomshardware.com/2000/07/31/intel/index.html) sure (http://www.trnicely.net/pentbug/bugmail1.html) they (http://www.pcworld.com/article/3848/intels_celeron_266.html) wouldn't (http://en.wikipedia.org/wiki/Pentium_4#Prescott).

No matter, though. If Intel's selling it as a 3GHz chip (I see 2.88GHz, not 3, but whatever), they're presumably relatively sure it's stable there and are willing to honor warranties for its performance and integrity at that speed. That's not so much overclocking by Intel as it is an improved yield on their lower-end bins. Given that all of these are the same silicon, just graded differently, it's not surprising that most specimens are flexible in their operational specifications. The latest generation are exceedingly flexible, which is a nice boon for the home builders. It's a good thing. Enjoy it, hopefully it lasts :).

The manufacturers make money off charging more for things that have little to no actual physical difference. I suppose it could be said that you're spending extra for a chip that's more likely to survive higher clocks, and the warranties therein. Either way, they don't want you screwing with it. And if it happens to cause problems for you or break, they're not going to be of any help at all if you do screw with it. There are a lot of people who value the system's stability and manufacturer support over sheer processor and/or memory performance. If you don't care about the warranties, go nuts. If you do care, you probably won't do it. Simple :).

[Cindori]

I oced my 1,1 MP 2.66 to 3.0 without crashes etc with that app. However you get a problem with the clock. since OSX reads time from FSB on Macpros, the clock will display wrong time. :(

[Loa]

Hello,

Reading some of you guys, it's clear that if you're right, a huge chunk of the CPU community at large are utter idiots just because they "consider" overclocking.

Now there may be some legitimate reasons for being wary and careful about overclocking. But the mere fact that so many "respected" sites talk about overclocking suggests that these reasons may not be all that significant for every CPU type.

Considering the premium that Apple charges to go from a octo 2.26 to an octo 2.93, I think that the reality distortion field is still in full effect!

:-)

Loa

[lemonade-maker]

It's not that overclocking is stupid. It's acually a pretty cool thing to do, as a hobby. Many people use there macs for projects where the project has enormous value. The computer is a essential piece and messing around with it can put an entire project at risk. It is very short sighted to see a computer as if it were a chevy 350 that you can get another 100 hp out of. For most people buying mac pros it's not worth the risk, even if it is very minimal.

[Matrixfan]

To be honest stable 3.5-4 Ghz is almost granted with 45nm technology at stock or nearly stock voltages. CPU frequency scaling is more of a business strategy than outcome of wafer yields. The Xeons aren't megical chips either, they are the same desktop processors complemented with ECC and multi processor support, that's all.

Regarding the Zdnet tool for 2008 Mac Pros the biggest problem is raising the fsb in conjunction with the memory clock. The CPU has a lot of headroom but the ECC FB-DIMM memory has almost none. There are no tuning server modules :) Someone mentioned instant kernel panics even at the slightest amount of overclocking. That is because of ECC failure and has nothing to do with the CPU. If only we could lock down memory frequency. My bigger concern is PCI-E frequency. That should be set at 100Mhz under any circumstances or it could damage cards.:apple:

[Apple //e]

its not hard to overclock without affecting stability and durability. its when youre pushing the limits that stability and heating and durability are affected. for most people who just want to get the most for their money, its not a problem.

but anyways, its all about warantees. i dont think there are many oems that allow overclocking in bios. apple is no exception.

if you want to overclock with pcs, you need an overclockable mobo (3rd party) and roll your own system.

im sure many hackintosh users have ocd systems, and im sure practically no one runs an ocd store bought hp pavilion

[lemonade-maker]

its not hard to overclock without affecting stability and durability. its when youre pushing the limits that stability and heating and durability are affected. for most people who just want to get the most for their money, its not a problem.

but anyways, its all about warantees. i dont think there are many oems that allow overclocking in bios. apple is no exception.

if you want to overclock with pcs, you need an overclockable mobo (3rd party) and roll your own system.

im sure many hackintosh users have ocd systems, and im sure practically no one runs an ocd store bought hp pavilion

Its not a matter of being reliable while oc'd or voiding a warranty. You don't tweak tools that produce results. If a project is worth lots of money and has series of deadlines, overclocking is just plain silly. The minimal risk of downtime could kill a project and in my case, cause liabilty issues. Also, if you oc a computer you are potentially putting the results at risk because the data can be wrong, especially if the data is time based.

[Apple //e]

Its not a matter of being reliable while oc'd or voiding a warranty. You don't tweak tools that produce results. If a project is worth lots of money and has series of deadlines, overclocking is just plain silly. The minimal risk of downtime could kill a project and in my case, cause liabilty issues. Also, if you oc a computer you are potentially putting the results at risk because the data can be wrong, especially if the data is time based.

apple, and other oems do not offer overclock setting because they dont want to deal with noobs calling about overheating, etc. so for the manufacturers, it is about customer support. for intel, its about replacing damaged chips. thats the way i see it

ive been overclocking since the p4 for work (and play) with no problems. i understand individual mileage may vary

its not for everybody, you need to know how to pick your parts and take the time to tweak it. i definitely would not overclock a stock system

[lemonade-maker]

apple, and other oems do not offer overclock setting because they dont want to deal with noobs calling about overheating, etc. so for the manufacturers, it is about customer support. for intel, its about replacing damaged chips. thats the way i see it

ive been overclocking since the p4 for work (and play) with no problems. i understand individual mileage may vary

its not for everybody, you need to know how to pick your parts and take the time to tweak it. i definitely would not overclock a stock system

You are right to a certain extent but I doubt customer support is a primary reason. The lower end macs maybe more so than the mac pros. People who use mac pros or sun workstations or even Dell workstations have actual real world work to do. Work that has a lot on the line. Yes the machines can run faster but for what purpose? These machines need to get the job done. Faster is nice but not at the expense of the project. I wouldn't put my life or the life of others on the line to have a marginally faster computer. You can build a bridge so it is just adequate strength-wise but there is a reason they are built much stronger than adequate. Same is true of professional level computers.

[Apple //e]

You are right to a certain extent but I doubt customer support is a primary reason. The lower end macs maybe more so than the mac pros. People who use mac pros or sun workstations or even Dell workstations have actual real world work to do. Work that has a lot on the line. Yes the machines can run faster but for what purpose? These machines need to get the job done. Faster is nice but not at the expense of the project. I wouldn't put my life or the life of others on the line to have a marginally faster computer. You can build a bridge so it is just adaquate stregthwise but there is a reason they are built much stronger than adaquate. Same is true of professional level computers.

like i said, its not for everybody. if you are not comfortable with bios settings or just dont know how - you should definitly not overclock

i personally have been overclocking my machines for work (cad and 3d rendering) for the past 8-9 years with zero issues. i dont spend all my time rendering, but when i do its usually near a deadline and cutting a 5 min preview render down to 3.5 mins is huge when the clock is ticking

in my case, the increase in rendering times (10-25%) is a productivity boost i can quantify in both time and money. NOT using my skills and knowledge to boost my productivity would be plain silly

[waffle911]

I agree with Apple//e in that respect.

There's overclocking for pure performance gains and then there's overclocking for efficiency. And it works the same way with the engine in a car.

You can tune the engine in a Honda Civic to get 600+hp if you really work at it. The legendary Nissan Skyline GTR and Toyota Supra both had 6-cylinder engines rated at 276hp, actually made somewhere north of 320hp, and could be tuned with relatively little effort to supercar-killing outputs of over 1100hp. But when you start pushing the envelope above 380hp, you really start to sacrifice ease of drivability and overall reliability. An old episode of Topgear that covered the older GTR mentioned that, if you were looking for one used, look for one that hadn't been 'chipped' for increased performance because the extra power (and there was always a lot of it) came at the expense of added wear on the turbocharger, which is very expensive to have rebuilt/repaired when it goes.

There are ways you can improve the performance of a Chevy truck, and they can help you out with whatever work you use it for. But after a certain point, added performance compromises long-term reliability/survivability, which increases overall operating costs rather than decreasing them. It was initialyl designed to be the best it could be for the price and engineering limitations when new. When it gets old, new technology can extend its usefulness and enhance performance. But after a point, it's purely enhancement for its own sake with no practical application, and it's time to consider a newer, better-from-the-get-go truck. Because after that point, you start getting into the territory of performance 350 small-blocks that are optimized for performance and as a result have to be rebuilt much more frequently to maintain that level of performance. Treat it like a normal engine and it will eventually throw a rod and punch a hole in the block, or eat the valvetrain, ending its life prematurely. I speak from experience. (Don't try doing a burnout down the street on a cold start without letting the engine warm up first. The expansion of metal due to heat in tight tolerances can cause huge problems. Ask an F1 team why the engine can't even be started until it's been pre-heated to operating temperature.)

A little performance boost can go a long way, but it's really not far before you go over the edge of reason when dealing with huge projects and operating costs. The risks become much, much tighter than in the world of hardware enthusiasts who push to get the bleading edge with little regard for longevity.

Also note that sites like Tom's Hardware even caution that overclocking leads to decreased lifespan of the hardware, regardless of any measures taken to reduce heat/etc. They say that to stay on the safe side, they overclock until system stability is compromised in the slightest, then back off to less than 80% of what they achieved (IIRC); this would last exponentially longer than it would at the bleeding edge, but still significantly shorter than if the chip were left bone stock. Most companies I know of are on a 5ish-year tech cycle, with some companies that require more high-performance equipment being on a 3-year cycle. Overclocking much outside the stock tolerances can easily bring the lifespan of a chip to be less than that. If you can afford to replace it every 1-2 years, then by all means do so. But often enough, the risk/cost vs. reward is just not at all favorable.

Also Loa, especially given that you joined MacRumors in 2003, you actually come off as sounding a bit like a Windows troll, or otherwise that you know surprisingly little about Apple's target market demographic.

[goMac]

Risk my $1000 CPU on overclocking? No thanks.

If I had a $100 i3, that's not much I'm risking, so sure.

[lemonade-maker]

It is true that you can mod a motor to produce crazy power. But it most likely doesn't have the brakes, clutch, transmission, motor mounts, chassis, or suspension to handle the power increase. So you spend a bunch of time fixing all this stuff as it breaks and in the meantime can't use the truck to get to the jobsite.

Overclocking is an enthusiast hobby. If you depend on it, it's best to leave it alone and trust the engineers that designed it. Anecdotal evidence doesn't prove this wrong.

[al2o3cr]

Why is overclocking such a big deal on the PC side, but not on the Mac side even though we're using the same family of chips?


Several reasons:

- Mac users typically have JOBS. People with jobs tend not to want to spend two weeks dicking around to get a 5% improvement on synthetic benchmarks.

- Because Mac users aren't this guy, who has apparently "overclocked" his spoiler:
http://failblog.org/2009/04/18/spoiler-fail/

- Because crashing every day or two (which a typical OCer will regard as "stable") isn't acceptable. Apparently, running Windows erodes one's expectations of computer reliability.

- Finally, a more practical reason: most of the affordable Mac models simply aren't terribly susceptible to modification. You can't whack a 900 gram jet-engine cooler inside of a Mini or an iMac, and OCing a laptop isn't likely to end well either. As for Mac Pro owners, see the first reason above. A recording engineer whose Mac Pro is turning out $100/hr+ work isn't interested in "mostly stable".

[Loa]

Wow, you just about sum up everything that seems wrong in so many Mac users' opinions.

- Mac users typically have JOBS.

WTF are you smoking man? More than 90% of computer users don't use Macs. Those 90% don't typically have jobs? Prejudiced a lot?

A recording engineer whose Mac Pro is turning out $100/hr+ work isn't interested in "mostly stable".

Someone in THIS THREAD, using his Mac professionally, said that he's been using overclocking for years. Read man. It's good for you.

Also, do you really think that all Mac users use their Macs on work/mission critical things?


I really don't know what it is about overclocking that makes you and so many others afraid. Interesting ppl have come to this thread, with good information, to tell us how OC can be a bad, or a good thing.

Yet so many others, like you, just add fears and frustrations and a heap of useless emotions. You have issues with OC, and somehow managed to make them personal. Couldn't care less about them, and I can't imagine anyone being interested in them on a Mac forum either.

My guess is that because of posts like yours, many ppl reading this thread looking for good info will just stop reading.


This entire thread has been a real eye opener. I now understand why there's so little info about OC...

Anyway, thx to you guys who bring real info/experience about OC to the thread. Here's hoping for more!

Loa

[lemonade-maker]

Wow, you just about sum up everything that seems wrong in so many Mac users' opinions.



WTF are you smoking man? More than 90% of computer users don't use Macs. Those 90% don't typically have jobs? Prejudiced a lot?



Someone in THIS THREAD, using his Mac professionally, said that he's been using overclocking for years. Read man. It's good for you.

Also, do you really think that all Mac users use their Macs on work/mission critical things?


I really don't know what it is about overclocking that makes you and so many others afraid. Interesting ppl have come to this thread, with good information, to tell us how OC can be a bad, or a good thing.

Yet so many others, like you, just add fears and frustrations and a heap of useless emotions. You have issues with OC, and somehow managed to make them personal. Couldn't care less about them, and I can't imagine anyone being interested in them on a Mac forum either.

My guess is that because of posts like yours, many ppl reading this thread looking for good info will just stop reading.


This entire thread has been a real eye opener. I now understand why there's so little info about OC...

Anyway, thx to you guys who bring real info/experience about OC to the thread. Here's hoping for more!

Loa

So you are advocating that I write my code that is a big dollar project on an overclocked Nehalem? No way. For you to spread that kind of misinformation is not good. 3d cad/game/net surfer maybe ( I wouldn't if I made my money on 3d cad) but no way on a real project.

I have overclocked many systems starting with a mac IIsi by replacing a crystal oscillator to go from 20 to 25 mhz and most recently a q6600 that is my family's main entertainment machine. It has its place. Its place is not a professional level machine, obviously not the realm you are in.

[goMac]

Yet so many others, like you, just add fears and frustrations and a heap of useless emotions. You have issues with OC, and somehow managed to make them personal. Couldn't care less about them, and I can't imagine anyone being interested in them on a Mac forum either.

No, you're asking about overclocking in a forum about Xeon based computers when several people have already told you that, unlike the Core series, Xeons are not meant to be overclocked.

That's why you don't see many people overclocking Mac Pros. No Xeon, from any vendor, is meant to be overclocked. Especially not the Nehelem Xeons.

Overclocking is mostly something for the Core/i3/i5/i7 series. Not the Xeon. You're simply looking in the wrong place.

A Google search will show that the Xeon is not meant to be overclockable, especially in dual processor configurations, due to the very specific timings of components. There are existing tools to overclock the 08 Mac Pros but it's very easy to mess up timings and cause the system to crash.

[Loa]

So you are advocating that I write my code that is a big dollar project on an overclocked Nehalem? No way. For you to spread that kind of misinformation is not good.

My point is that what you (and others) chose to do in with your own computers has no bearing on this thread at all. I'm not spreading misinformation, nor am I advocating for anything.

I was asking for actual information. Like this:

Xeons are not meant to be overclocked.That's why you don't see many people overclocking Mac Pros.

And I thank those 2-3 ppl that offered it.

But you have to marvel at the overflow of prejudice, emotions and utter mis-information that came along with it. My question has been answered quite a few posts ago; my fascination with this thread just keeps growing.

The mere fact that I was likened to a PC troll is laughable. I simply asked a question. But obviously the subject is touchy enough that it triggered nerves in a lot of ppl. Sorry if some people think that I "wanted" to spark a confrontation. I've never owned a PC in my life, even though I've been using computers everyday since getting my Mac Plus.

Sigh. Touchy subject, touchy people...

Loa

[cmaier]

:D That it is. If I wasn't a student, I swear... :o



Read about it on Wikipedia and have a good idea of what it does and how it works; do you have any more information specific to the matter? Something you've read, pertaining to overclocking?

I designed CPUs at AMD for 10 years. I wrote the software tool we used to figure out where to beef up wires and vias to ensure the proper life time given electromigration (among other tools).

Electromigration is a real and serious problem. However, in modern CPUs, most of the current will likely be bidirectional current. As a result, increasing the clock frequency will have little effect. Older Intel CPUs which relied more on dynamic logic would be more of a problem.

[lemonade-maker]

My point is that what you (and others) chose to do in with your own computers has no bearing on this thread at all. I'm not spreading misinformation, nor am I advocating for anything.


If you are saying that overclocking is nothing to be afraid of, you are advocating. It is something to be afraid of, the amount of fear that is tolerable or minimized is the question. If you can minimize or tolerate the odds of failure, oc may be for you. If you can't then don't. Most people that buy Mac Pros depend on them working and therefore can't or won't tolerate the risks no matter how small it is.

It seems you don't like some of the answers you got so that leads to the question of trolling.

[Techhie]

If you are saying that overclocking is nothing to be afraid of, you are advocating. It is something to be afraid of, the amount of fear that is tolerable or minimized is the question. If you can minimize or tolerate the odds of failure, oc may be for you. If you can't then don't. Most people that buy Mac Pros depend on them working and therefore can't or won't tolerate the risks no matter how small it is.

It seems you don't like some of the answers you got so that leads to the question of trolling.

It's ironic that you bring up the word "troll" considering the majority of your posts in this thread contain no viable information and taunt users.

[lemonade-maker]

It's ironic that you bring up the word "troll" considering the majority of your posts in this thread contain no viable information and taunt users.

I don't see the irony. How did I "taunt"? You don't have to agree with my reasons for not overclocking a mac pro. The reasons are "viable" though.

[snouter]

On the PC side of things, you can't much overclock the Xeon on Xeon motherboards either.

As far as the i7 goes, my understanding is that the i7 Bloomfield chips are are the same. The ones that test out better become the Extreme and higher clocked CPUs. What this means is that if Intel is on their game, and getting good yields, then very good quality CPUs end up become the i7 920. This is part of why they overclock so well.

As far as instability, I've never much had a problem? I hear the i7 920 can get to 4GHz, but, I've never taken it above 3.6 and usually stay in the 3.2-3.4 range. The only thing I notice is that my rendering and compression times drop. lol

I change one setting in the BIOS, and bam, new higher speeds. My last dekstop, an AMD 3800+ was also as simple to overclock, with no issues that I am aware of other than a faster computer.

[Dr.Pants]

I designed CPUs at AMD for 10 years. I wrote the software tool we used to figure out where to beef up wires and vias to ensure the proper life time given electromigration (among other tools).

Electromigration is a real and serious problem. However, in modern CPUs, most of the current will likely be bidirectional current. As a result, increasing the clock frequency will have little effect. Older Intel CPUs which relied more on dynamic logic would be more of a problem.

Thanks for your input.... but I'm curious as to why having dynamic logic would have a greater electromigration effect. I'm sorry, my knowledge of circuits is rudimentary at best (i.e., 200-level physics).

Also, (pardon me for being a layman) I would assume that as dies continually shrink, the power density being put through them would have to decrease in order to balance things (Black's equation) out? I understand that Black's equation isn't real life, but I assume that all other factors being the same both have to trend downward.....

[xgman]

Hahaha,

Thanks for the EFI-BIOS replies!

For the rest... funny replies! Sounds like GM employees defending their company's bad decisions.

Judging from *most* of the replies, we don't have OC on Macs because most ppl are:

-afraid
-prejudiced
-using knowledge that is decades old

Read up on what's possible on simple i3 chips today. Going from 2.93 to 4. Without using extra cooling. With stability.

If i3 chips can do that, what can the workstation grade CPUs in our MPs do?

I'm aghast at the tone of most replies!

Loa


As you probably know, the costs of some of the pc counterparts are equally as high if not higher than a mac pro and that never stopped an overclocker from messing about. The zdnet tool works depending on how good your ram is I've come to find out, but I've also resigned myself to the fact that if I really wanted to overclock for whatever reason, it is far easier on a pc or even a mac clone and not really worth the effort on a mac pro. Anyway as a long time pc overclocker, that isn't why I bought a MP. What most mac users don't understand is that pc overclocking is a hobby. It's fun. It can be challenging and you learn a great deal along the way. I'm not sure why some people get so worked up about the dangers and reasons we do it. No one is forcing them to even read this. Oh well......

[cmaier]

Thanks for your input.... but I'm curious as to why having dynamic logic would have a greater electromigration effect. I'm sorry, my knowledge of circuits is rudimentary at best (i.e., 200-level physics).

Also, (pardon me for being a layman) I would assume that as dies continually shrink, the power density being put through them would have to decrease in order to balance things (Black's equation) out? I understand that Black's equation isn't real life, but I assume that all other factors being the same both have to trend downward.....

In static CMOS the current tends, over time, to be zero. In other words, for every cycle in which, for a given wire, current flows in one direction, in another cycle it will flow in the opposite direction.

In some types of dynamic circuits this is not the case- current always flows in the same direction.

Electromigration occurs in the direction opposite current flow, as electrons essentially carry away molecules of the metal. If you have bidirectional current, electromigration is much less of a problem as the net effect cancels out- before my molecule gets very far, the current reverses and brings it back.

Yes, as metal dimensions decrease we worry much more about electromigration - but usually there aren't too many wires susceptible and we beef them up with lots of vias, increased width, etc.

[Dr.Pants]

In static CMOS the current tends, over time, to be zero. In other words, for every cycle in which, for a given wire, current flows in one direction, in another cycle it will flow in the opposite direction.

In some types of dynamic circuits this is not the case- current always flows in the same direction.

Thanks for the info, cmaier.

[drrbc]

but the shear volume of FUD made me.

Watch closely for a stable 4Ghz within 1 month.

[Tutor]

Why overclock if you can underclock your way to the highest performance. I used to only be a stay-within-spec-VID overclocker (still am a stay-within-spec-VID overclocker only where all attempts at underclocking fails). But I have now discovered the rewards that underclocking and turbo biasing bring: 1) Keeps those voltages within spec VID. 2) Keeps system and CPU (and cores within) cooler. 3) Keeps power company at bay, lower current draw. Upon load, aren't these the relevant factors determining whether turboboosting occurs? Turbo biasing now at DDDDEE (13,13,13,13,14,14 [27 - 13 = 14; 26 - 13 = 13]), with HPET 64, C1E, C-states, P-states, T-state and all other native power management features fully enabled, running dual 5680s rated at 3.33 GHz, but running them at under 2.5 GHz. Click URL in sig, then click/filter scores, comparing scores with frequencies. All systems are completely stable - both O'ced and U'ced ones. And as for that knock against overclockers using the longevity/stability card, my overclocked 1) Atari TT030, 2) Amiga 500, 2000s, 3000 [with Video Toaster] and 4000 [with Video Toaster], and 3) Apple Power PC 7500, 8500s, 9600 are all still running fine in my studio. Getting over 17 years of regular use from these modified antiques counters the longevity/stability arguments of those who have never gotten to know their system's potential fully. And yes, I have two overclocked iMac (the original ones with those weird colors) and three Mac Pro 2,1's rated at 3.0 Ghz, overclocked to 3.6-3.7 GHz, using 800 MHz memory and a modified version of Zdnet's utility and expect to have them all, as well as all of my other post-2000 modified systems that I don't gift, running stably when I'm in my 70's - twelve years from now.

[derbothaus]

but the shear volume of FUD made me.

Watch closely for a stable 4Ghz within 1 month.

Thanks for the resurrection.
Not sure what this means either. GoMac claimed in this thread that Xeons are not meant to overclock. WTF? Some of the best overclocks I have ever seen were on Xeons. You can overclock a Xeon Hex to at least 5.4GHz in right environment. I saw a a W3690 hit 6.1GHz. Intel will not be selling a default 4GHz clock for at least a year. Their turbo bins may hit it but they are holding steady at 3.9GHz for turbo even through Ivy Bridge.
Truly you have to be real timid to be scared of overclocking and ruining the chips. You may ruin the board before you ruin the chip. Overclocking has tremendous advantages. Like paying 200.00 for a core 2 duo that can stably clock beyond the 1000.00 part. I had a conroe 2.66GHz that ran for 3+ years at 3.66GHz and it was locked! Made huge difference in my game smoothness. Actually that proc is still going strong with a milder OC for my father at 3.06GHz. It is kind of like a car, just bang it into submission.

[drrbc]

Why overclock if you can underclock your way to the highest performance...

Oh, I gotta know how you can underclock and volt a Nehalem- is it Reggie?

I've heard of overclocking one by cutting a PLL clock gen (I think). Gotta tell how!

[Bob Kiwi]

three Mac Pro 2,1's rated at 3.0 Ghz, overclocked to 3.6-3.7 GHz, using 800 MHz memory and a modified version of Zdnet's utility and expect to have them all, as well as all of my other post-2000 modified systems that I don't gift, running stably when I'm in my 70's - twelve years from now.

I'm intrigued by this, as I too have a 2,1 @ 3GHz and would love to hear more about getting 800MHz memory and modified Zdnet tool. Care to explain a little on how you got that set up?

[Tutor]

I'm intrigued by this, as I too have a 2,1 @ 3GHz and would love to hear more about getting 800MHz memory and modified Zdnet tool. Care to explain a little on how you got that set up?

Bought from Newegg the 800 MHz memory they recommend for the Mac Pro 2008. As for the software, simply download it and first try it as is because mileage varies. If you can reach their limit stably, then PM me.

Caveat: I have decided to stick with SL 10.6.7 for all of my systems that handle SL, except for one of my 2009->2010 Mac Pros and one of my MBpros. So I'd recommend that you first download the software from ZDnet before investing in the memory to see if you can run the software with whatever version of OSX you have.

----------

I'm intrigued by this, as I too have a 2,1 @ 3GHz and would love to hear more about getting 800MHz memory and modified Zdnet tool. Care to explain a little on how you got that set up?

Oh, I gotta know how you can underclock and volt a Nehalem- is it Reggie?

I've heard of overclocking one by cutting a PLL clock gen (I think). Gotta tell how!

I've sent a private message (PM) to you.

[ekwipt]

Thanks for the resurrection.
Not sure what this means either. GoMac claimed in this thread that Xeons are not meant to overclock. WTF? Some of the best overclocks I have ever seen were on Xeons. You can overclock a Xeon Hex to at least 5.4GHz in right environment. I saw a a W3690 hit 6.1GHz. Intel will not be selling a default 4GHz clock for at least a year. Their turbo bins may hit it but they are holding steady at 3.9GHz for turbo even through Ivy Bridge.
Truly you have to be real timid to be scared of overclocking and ruining the chips. You may ruin the board before you ruin the chip. Overclocking has tremendous advantages. Like paying 200.00 for a core 2 duo that can stably clock beyond the 1000.00 part. I had a conroe 2.66GHz that ran for 3+ years at 3.66GHz and it was locked! Made huge difference in my game smoothness. Actually that proc is still going strong with a milder OC for my father at 3.06GHz. It is kind of like a car, just bang it into submission.

I think it was said that with Xeon motherboards which is probably true (super micro, Tyan etc)

[Atomic101]

I overclock my Mac Pro 2008. I have been overclocking for 2 years at 3.15ghz -no problems at all, no crashes, 3day renders complete fine. This has saved me days of time & on occasion it was the only way to achieve my deadlines & It also improves the speed of my graphics card.

@ drrbc 4ghz ? -this on mac pro 1.1 tell me more.. Just got my x5482's trying for 3.55 on my 3.1 Pro & have been looking at water cooling. What blocks do you use ?

[drrbc]

I overclock my Mac Pro 2008. I have been overclocking for 2 years at 3.15ghz -no problems at all, no crashes, 3day renders complete fine. This has saved me days of time & on occasion it was the only way to achieve my deadlines & It also improves the speed of my graphics card.

@ drrbc 4ghz ? -this on mac pro 1.1 tell me more.. Just got my x5482's trying for 3.55 on my 3.1 Pro & have been looking at water cooling. What blocks do you use ?

Well, it should be easy to figure out if ya look at my sig- but any way...

I got a 1,1 with 5350's BSEL'd to 3.3 (using Koolance CPU 340's). VID'd to 1.4125- I think. Will try the 1600 BSEL with new 800Mhz RAM (shout out to Grant at OWC). if that don't work then will try Netkas' 1,1 to 2,1 utility. If not that then I'm dropping them into a 3,1 to see what happens.

The 3,1 is to be my new main gizmo. Got some 5460's for it. See no reason why can't get 3.8 outta it.

Main thing holding me back currently is time to fabricate the waterblock's for the RAM. Havent even started the PSU yet, but that should be easier than the RAM (famous last words- ZAP!)

Bad need of expanding the GHX I'm currently using. Last on the list is to cool two 30" ACD's. I'm expecting to about double the watts into the dirt to @ 2200. In bad need to find a way to get some 10' sections of copper pipe 20' straight down on the cheap. Any PetE's or ME's in the Houston area willing to work for beer?

Later, I've got parts for a sub $2k 5,1 "FrankenMac". But not as interesting to me as the 3,1- but should be an attractive machine anyway. Hope to Geekbench 20k on it.