Mac Rumors second official 3.33 Ghz Nehalem 2009 Mac Pro

[AppleWorking]

The difference is you get ECC memory support with the Xeon (and Direct Cache Access, but that is more a server thing from what I've read). Buy the cheapest if you don't care about ECC.

Will the fact that no ECC support on the i7 somehow break the compatibility of the i7 when snow leopard or a future OS is released? I know no one can say for certain, but someone who knows a lot take a educated guess... Because if it might, I would think paying a little more for the W3580 CPU now would be worth it in the end?

 

[Umbongo]

Will the fact that no ECC support on the i7 somehow break the compatibility of the i7 when snow leopard or a future OS is released? I know no one can say for certain, but someone who knows a lot take a educated guess... Because if it might, I would think paying a little more for the W3580 CPU now would be worth it in the end?

There should be no issue with it if there isn't currently (which there doesn't appear to be). It's a hardware thing not software. Software just reports it. As I understand ECC anyway.

 

[AppleWorking]

There should be no issue with it if there isn't currently (which there doesn't appear to be). It's a hardware thing not software. Software just reports it. As I understand ECC anyway.

Thanks, i'm going to pull the trigger but I just want to make sure the W3580 CPU is not the best bet over the i7. If anyone knows anything please stop me. I'm a little anal and worry if something could go wrong with the i7 over the W3580, but then again i'm a little tight so the discount on a i7 is tempting.

 

[nanofrog]

Will the fact that no ECC support on the i7 somehow break the compatibility of the i7 when snow leopard or a future OS is released? I know no one can say for certain, but someone who knows a lot take a educated guess... Because if it might, I would think paying a little more for the W3580 CPU now would be worth it in the end?

Umbongo's right, it's hardware, not software. The system can still use the memory (just not the ECC function), so no need to worry about the system suddenly not working when you change to SL.

 

[AZREOSpecialist]

For what it's worth, I've been running now for 2 weeks without a hiccup. I had a kernel panic the other day when waking from sleep, but I often had those with my G5 Power Mac so it didn't really phase me. CPU temps still average about 37-38 degrees under average office use.

If SL requires ECC RAM, then unfortunately it would not run on any Apple laptop or iMac. My inclination is to believe that the OS will detect and support it, but will not render your machine inoperable if it's not there. Only Mac Pros use ECC RAM, and in all likelihood they won't be using it in the future.

I say give it a shot!

Thanks, i'm going to pull the trigger but I just want to make sure the W3580 CPU is not the best bet over the i7. If anyone knows anything please stop me. I'm a little anal and worry if something could go wrong with the i7 over the W3580, but then again i'm a little tight so the discount on a i7 is tempting.

 

[Umbongo]

Only Mac Pros use ECC RAM, and in all likelihood they won't be using it in the future.

Yeah they will. However unlikely the chance of an error that can be corrected causing a flaw in your data is, it is still one that can be removed. So while Mac Pros are being used as workstations ECC will be there.

 

[AZREOSpecialist]

As unlikely as a gamma ray burst aimed directly at the Earth from a super nova in a galaxy a billion light years from our own?

Yeah they will. However unlikely the chance of an error that can be corrected causing a flaw in your data is, it is still one that can be removed. So while Mac Pros are being used as workstations ECC will be there.

 

[Umbongo]

As unlikely as a gamma ray burst aimed directly at the Earth from a super nova in a galaxy a billion light years from our own?

White papers and studies put error rates at 1+ per day on 4-8GB. ECC is essential in a datacenter, the same chipset and processors will continue to be used in both the server and workstation lines, Apple will use both in their products. Therefore Apple will continue to offer ECC memory.

 

[TheSilencer]

AFAIK the OS also does some checking when reading RAM contents so ECC basically isn´t that needed especially thinking of usual gaming rigs and office computers which run cheap usual memory and have no problems.

Why not considering an upgrade with an XEON W3580 or W3570? Sadly the W3580 is not available yet, but the XEONs have one benefit over the i7 - 4C Turbo, meaning all cores can Turbo Boost +133MHz, not only one core like the i7.
The XEON is more expensive, yes, but you also have to buy non ECC RAM for it or does work the stock RAM with it, just disabled ECC?

 

[AZREOSpecialist]

I do not believe this is correct. The Core i7 is the same basic architecture as the Xeon and all the information I could find points to the Core i7 975 Extreme having the same Turbo Boost functionality as the Xeon. Some reports even indicate that the Turbo Boost in the Core i7 Extreme Editions are higher than the Xeons.

AFAIK the OS also does some checking when reading RAM contents so ECC basically isn´t that needed especially thinking of usual gaming rigs and office computers which run cheap usual memory and have no problems.

Why not considering an upgrade with an XEON W3580 or W3570? Sadly the W3580 is not available yet, but the XEONs have one benefit over the i7 - 4C Turbo, meaning all cores can Turbo Boost +133MHz, not only one core like the i7.
The XEON is more expensive, yes, but you also have to buy non ECC RAM for it or does work the stock RAM with it, just disabled ECC?

 

[AZREOSpecialist]

Here is the link to Intel's page on Turbo Boost. It works the same on the Core i7 as it does on the Xeon and boosts active cores (plural).

 

[AppleWorking]

Hey, thanks everyone for the info. After reading a ton of articles on the net in regard to a Xeon versus a Core i7 it appears that in addition to the ECC support, the Xeon processors are cherry picked. They run cooler out of the box and run more efficiently at less power. They are less prone to failure, etc. You can also buy them now from a few places for about $160 more than the i7 975, but I still don't know if it's worth it??? I also hear that a xeon mobo can get confused about the model when a i7 is installed instead. hmmm, but for $160 more on an already expensive as hell upgrade... I just don't know....

 

[AZREOSpecialist]

Where are you getting your pricing? The lowest price I can find for the W5590, which is the only Xeon equivalent to the Core i7 975 Extreme, is around $1,600 while the i7 975 Extreme is running about $980. That's over $600 difference for one chip.

I use my Core i7 975 Extreme Quad Mac 12 hours a day here at work, and never once had an issue. Perhaps I'm reading conflicting information, but the Core i7 Extremes are supposed to run cooler and have much more overhead for over clocking and Turbo Boost versus the Xeon parts. Perhaps PC motherboards have difficulty recognizing a Core i7, but not the Mac Pro. My experience is that it just works. I even have 16 GB of RAM which Apple doesn't even acknowledge in its Quad specs, and it works just fine.

Hey, thanks everyone for the info. After reading a ton of articles on the net in regard to a Xeon versus a Core i7 it appears that in addition to the ECC support, the Xeon processors are cherry picked. They run cooler out of the box and run more efficiently at less power. They are less prone to failure, etc. You can also buy them now from a few places for about $160 more than the i7 975, but I still don't know if it's worth it??? I also hear that a xeon mobo can get confused about the model when a i7 is installed instead. hmmm, but for $160 more on an already expensive as hell upgrade... I just don't know....

 

[AZREOSpecialist]

One more thing... I am 99% certain that you won't have any issues with a Core i7 975 Extreme in your Quad given my own experience. However, in the unlikely event that you do have an issue, you can re-sell your 975 on eBay for approx. $700.

Hey, thanks everyone for the info. After reading a ton of articles on the net in regard to a Xeon versus a Core i7 it appears that in addition to the ECC support, the Xeon processors are cherry picked. They run cooler out of the box and run more efficiently at less power. They are less prone to failure, etc. You can also buy them now from a few places for about $160 more than the i7 975, but I still don't know if it's worth it??? I also hear that a xeon mobo can get confused about the model when a i7 is installed instead. hmmm, but for $160 more on an already expensive as hell upgrade... I just don't know....

 

[AppleWorking]

Where are you getting your pricing? The lowest price I can find for the W5590, which is the only Xeon equivalent to the Core i7 975 Extreme, is around $1,600 while the i7 975 Extreme is running about $980. That's over $600 difference for one chip.

Hey, AZREO I must be confused... I thought the Xeon W3580 was the equivalent of the i7 975 Extreme? Here are the specs of the Xeon...


http://www.cpu-world.com/CPUs/Xeon/Intel-Xeon W3580 - AT80601002274AB (BX80601W3580).html

Don't you think this is the better buy (for me)? I mean safer for someone anal (like me)? LOL

BTW, I appreciate all your help bud.

 

[AZREOSpecialist]

Never mind, i'm an idiot. I am comparing apples and oranges. The W5590 is for dual processor configurations (2 QPI interconnects) which is not what you need. You want the W3590 which is a 3.33 GHz equivalent of the Xeon that ships with the Quad from Apple. That is priced only $100 or so more than the Core i7 Extreme 975.

All of these variations from Intel have me terribly confused. If you want the fastest Xeon for your Quad that supports ECC memory, you should get the W3590. It's a Xeon part and should alleviate most of your upgrade fears. The part in the 2.66 Quad is a W3520. Someone please correct me here, but isn't the only difference between the W3590 and Core i7 975 Extreme that the W3590 supports ECC and the 975 doesn't? Also, the 975 has unlocked multipliers which makes it easier to over clock for folks on the PC side and for the Hackintosh crowd.

Hey, AZREO I must be confused... I thought the Xeon W3580 was the equivalent of the i7 975 Extreme? Here are the specs of the Xeon...


http://www.cpu-world.com/CPUs/Xeon/Intel-Xeon W3580 - AT80601002274AB (BX80601W3580).html

Don't you think this is the better buy (for me)? I mean safer for someone anal (like me)? LOL

BTW, I appreciate all your help bud.

 

[nanofrog]

Never mind, i'm an idiot. I am comparing apples and oranges. The W5590 is for dual processor configurations (2 QPI interconnects) which is not what you need. You want the W3590 which is a 3.33 GHz equivalent of the Xeon that ships with the Quad from Apple. That is priced only $100 or so more than the Core i7 Extreme 975.

All of these variations from Intel have me terribly confused. If you want the fastest Xeon for your Quad that supports ECC memory, you should get the W3590. It's a Xeon part and should alleviate most of your upgrade fears. The part in the 2.66 Quad is a W3520. Someone please correct me here, but isn't the only difference between the W3590 and Core i7 975 Extreme that the W3590 supports ECC and the 975 doesn't? Also, the 975 has unlocked multipliers which makes it easier to over clock for folks on the PC side and for the Hackintosh crowd.

W35xx parts = Single Processor Board Xeon (single QPI)
W55xx parts = Dual Processor Board Xeon (dual QPI)

Fairly easy.

 

[AZREOSpecialist]

What are the differences between the W35XX series Xeon parts and the Core i7 975 Extreme CPU? Does it just come down to ECC memory?

W35xx parts = Single Processor Board Xeon (single QPI)
W55xx parts = Dual Processor Board Xeon (dual QPI)

Fairly easy.

 

[nanofrog]

What are the differences between the W35XX series Xeon parts and the Core i7 975 Extreme CPU? Does it just come down to ECC memory?

Yep.

Keep in mind, the "cherry picked' selections aren't that different in this case. They're off the same wafer, unlike the LGA1156 parts (some as i5, some as i9). Now those are confusing.

 

[AppleWorking]

Yep.

Keep in mind, the "cherry picked' selections aren't that different in this case. They're off the same wafer, unlike the LGA1156 parts (some as i5, some as i9). Now those are confusing.

I also read this about these unlike the older CPUs, the difference isn't that big like in the past. I've been reading a lot and the consensus is that they're pretty much the same except for the ECC. But they are selected by Intel as the better ones even if very similar. They're also unlocked like the i7s and guys who OC usually want the Xeons because they can OC even more.

For me, though, I could care less about OCing since we can't do it on a mac with these particular CPU's anyway (no app). I just want the one that will be the safest bet, and although saving $100 haunts me to no end as a tight wad I canceled my i7 order just now and bought the Xeon instead.

So I guess you could say I'm happy and sad. LOL

 

[nanofrog]

I also read this about these unlike the older CPUs, the difference isn't that big like in the past. I've been reading a lot and the consensus is that they're pretty much the same except for the ECC. But they are selected by Intel as the better ones even if very similar. They're also unlocked like the i7s and guys who OC usually want the Xeons because they can OC even more.

For me, though, I could care less about OCing since we can't do it on a mac with these particular CPU's anyway (no app). I just want the one that will be the safest bet, and although saving $100 haunts me to no end as a tight wad I canceled my i7 order just now and bought the Xeon instead.

So I guess you could say I'm happy and sad. LOL

Architecually speaking, ECC is the difference.

I don't consider the multipliers an issue, as even the parts with locked multipliers can be OC'd with the right board. Binning has more to do with finding the parts that are most stable a higher clocks, and to power usage as a side effect of that process.

I'm running an i7-920 ATM, and it's running fairly cool (for a Nehalem). Of course, if there's a shortage of a particular part number, even the best units (via binning) could be diverted to fill the "hole" as it were. So that explains why some have gotten better performance on the OC side than others, that's apparently not just board related.

 

[AZREOSpecialist]

Something to think about as well with ECC memory is that there is a performance penalty of 3-4% on memory reads. Here is what I found on AnandTech:

Performance. The ECC calculation process results in a small but measurable decrease in performance. The redundant ECC bits are calculated when ECC is written back to memory, and so a read-after-modified-write will incur a minor performance penalty. This reduction in performance is usually approximately 3-4%...​

I'm assuming that you would not incur this penalty with a Core i7. Is this correct, and is this even anything to worry about? There is an additional 3-5% speed penalty if you max out all four of your memory slots, so the two combined are knocking on 10% which seems like it could make a difference in some situations. Or perhaps this is something that will only show up on benchmarks and would have no impact on real world performance.

Any ideas?

 

[nanofrog]

Something to think about as well with ECC memory is that there is a performance penalty of 3-4% on memory reads. Here is what I found on AnandTech:

Performance. The ECC calculation process results in a small but measurable decrease in performance. The redundant ECC bits are calculated when ECC is written back to memory, and so a read-after-modified-write will incur a minor performance penalty. This reduction in performance is usually approximately 3-4%...​

I'm assuming that you would not incur this penalty with a Core i7. Is this correct, and is this even anything to worry about? There is an additional 3-5% speed penalty if you max out all four of your memory slots, so the two combined are knocking on 10% which seems like it could make a difference in some situations. Or perhaps this is something that will only show up on benchmarks and would have no impact on real world performance.

Any ideas?

ECC does slow you down a little bit, as it adds a clock cycle to the latency (i.e. CAS Latency = 7 when non ECC can have CAS Latency = 6 for example wit DDR3).

You won't see this with an i7, and why I'm not sure if I'll ever go with the Xeon on my board (orignally intended to use ECC, and bought a board that supports both i7 & Xeon). Not completely about performance, but I'm not having any issues so far.

When you max out the DIMM slots, it reverts back to dual channel, and that's the main reason for the performance differences there. However, not much software can even take advantage of triple channel memory throughputs, so it may be a non issue for you (in respect to channel configuration), unless you're running the system as a server (where triple channel does get used, as that's the realm of the limited software).

 

[AppleWorking]

Something to think about as well with ECC memory is that there is a performance penalty of 3-4% on memory reads. Here is what I found on AnandTech:

Performance. The ECC calculation process results in a small but measurable decrease in performance. The redundant ECC bits are calculated when ECC is written back to memory, and so a read-after-modified-write will incur a minor performance penalty. This reduction in performance is usually approximately 3-4%...​

I'm assuming that you would not incur this penalty with a Core i7. Is this correct, and is this even anything to worry about? There is an additional 3-5% speed penalty if you max out all four of your memory slots, so the two combined are knocking on 10% which seems like it could make a difference in some situations. Or perhaps this is something that will only show up on benchmarks and would have no impact on real world performance.

Any ideas?

Hi there,

I just found something interesting on Intel's site. It's a comparison of the two. Looks like a few of the specs are different...

http://ark.intel.com/Compare.aspx?ids=39723,37153,

As far as ECC goes I'm sure there is a performance penalty, but because macs are so sensitive to memory errors, I would prefer the ECC support. Plus it's a fast way to see if you have some bad modules (or going bad) by looking at the ECC errors instead of running memtest. For me anyway, I feel pretty content having spent the little extra. I could be worrying for nothing, but it just let's me sleep better at night.

Plus if I ever had to dump it off on eBay I'm sure the Xeon would bring more since "geeks" want them and there are so few listed.

 

[nanofrog]

Hi there,

I just found something interesting on Intel's site. It's a comparison of the two. Looks like a few of the specs are different...

http://ark.intel.com/Compare.aspx?ids=39723,37153,

As far as ECC goes I'm sure there is a performance penalty, but because macs are so sensitive to memory errors, I would prefer the ECC support. Plus it's a fast way to see if you have some bad modules (or going bad) by looking at the ECC errors instead of running memtest. For me anyway, I feel pretty content having spent the little extra. I could be worrying for nothing, but it just let's me sleep better at night.

Plus if I ever had to dump it off on eBay I'm sure the Xeon would bring more since "geeks" want them and there are so few listed.

All I can see, is the support for 1333MHz memory on the Xeon parts, which is what explains the additional bandwidth. (Other than ECC support of course).

I do like ECC, and the ability to check for memory errors is nice. I may go ahead and switch at some later date (if I can locate a part I'd want for the right price). But for now, I'll stick with what I've got.