AMD Radeon R9 M290x vs M295X

[joema2]

According to your graph...my late 2009 2.8GHz i7 iMac "should not be significantly slower" in terms of CPU performance with even the latest BTO i7 iMac, which has a base clock of 4.0GHz and Turbo Boost to 4.4GHz...there have been improvements to CPU clock speed since 2009, much more since 2006.

You cherry-picked a single example. It does not reflect the general plateau in CPU clock rates which have existed since about 2006-2007. People should not expect that Broadwell will be the "the biggest performance leap".

This is generally known and is described in the ExtremeTech article you quoted:

"On the CPU side, don’t look for much — Intel claims Broadwell is up to 5% faster than Haswell...Real life impact is likely to be in the 2-3% range. That would be normal — Intel’s die shrinks tend to offer only minimal performance improvements."

This article demonstrates how CPU clock rates and IPC improvements have plateaued: http://www.extremetech.com/computin...rom-one-core-to-many-and-why-were-still-stuck

....How then can it be accurately and effectively argued that Broadwell will be somehow insignificant or apply merely to putting 8 cores on the chip?

I am not saying that Broadwell will have insignificant performance gains, only that the clock rate will not be cranked up "noticeably higher than was possible before".

The main source of forthcoming performance gains will not be from higher clock rate or improved Instructions Per Cycle efficiency (IPC). Rather it will be from more CPU cores, faster GPUs, and instruction set enhancements like vector instructions, Quick Sync, etc. Except for more cores, these are narrow-purpose, not generalized performance improvements.

The reasons for this is well known in the CPU engineering community. Since hitting the plateau last decade, clock rates can't be pushed much higher. CPU designers have already exhausted most of the possible IPC improvements. For more info see: https://en.wikipedia.org/wiki/Superscalar

That leaves only higher core counts and specialized instructions/subsystems as the path forward. E.g, the latest Xeon E5-2600 v3 has 18 cores.

 

[cardfan]

I'd recommend the base unit. Get a deal at best buy. Plan on selling it in a couple of years and by then you have more options such as 5k monitors, better iMacs (that can be used as a monitor as well), etc.

You're buying the retina iMac for it's screen for the short term, not killer performance, and certainly not 5 years into the future. An i5 and 290x will get you by. Don't sink more money into this than you need to right now in order to satisfy your retina wants.

You'll take a hit with selling. But you're already thinking of blowing 500 on upgrades that you most likely won't even take advantage of.

 

[5iMacs]

Good points.

It's simply not logical to insist on nothing less than the fastest possible iMac today, and then expect to be happy with it for >3 years at which time it will be dramatically slower than new base models.

 

[rainydays]

Good points.

It's simply not logical to insist on nothing less than the fastest possible iMac today, and then expect to be happy with it for >3 years at which time it will be dramatically slower than new base models.

I'd say that it depends a lot on what you do with it and how your requirements change over the years.
Just because there are faster models available doesn't mean that you can't be happy with what you got. Those days when upgrading the CPU every three years would make a dramatic difference is over.
I see people working with their 5 year old MBPs just as happily as they did when they got them. An SSD and RAM upgrade put at least another 3 years of good use in them.

CPU power has surpassed the need of many users, even pro users. But we might see a dramatic shift in software that changes all that, who knows.

To me the retina display is a far bigger jump than twice the CPU power would be.

 

[JDW]

People should not expect that Broadwell will be the "the biggest performance leap".

I never said "biggest." I merely said Broadwell could be worth waiting for.

I am not saying that Broadwell will have insignificant performance gains, only that the clock rate will not be cranked up "noticeably higher than was possible before".

But your argument does appear to proclaim, "Broadwell really won't be as great as some think and therefore probably isn't worth waiting for."

As I said before, an increase from 2.8GHz (within the heat limits of an iMac chassis) in late 2009 to 4.4GHz (Turbo Boost speed) of the late 2014 Retina iMac is noteworthy TO ME. It's not like we've been stuck at 3.00GHz for the last 5 years. If one wishes to argue that CPUs clock speed really isn't noteworthy, then one would be better off with a 12 core Mac Pro rather than a four or six or eight core Mac Pro or a higher clocked iMac.

The main source of forthcoming performance gains will not be from higher clock rate or improved Instructions Per Cycle efficiency (IPC). Rather it will be from more CPU cores, faster GPUs, and instruction set enhancements like vector instructions, Quick Sync, etc. Except for more cores, these are narrow-purpose, not generalized performance improvements.

I agree somewhat, but I am excluding GPUs in this discussion which centers on "Broadwell." And in terms of "more CPU cores," as I said before, there are a number of Mac Pro buyers who forgo the 12 core model simply because as you increase the cores the clock speed decreases (due to heat management) and there are some serious disadvantages to reduced clock speed. If every little splattering of code within OS 10 was fully optimized for 12 or 24 or 48 cores, then you would be absolutely 100% correct that more cores would directly translate into noticeably improved performance for everyone, regardless of the apps will use. But for now there is very little multi-core software optimization which means that multiple cores are in fact targeting "narrow purpose, not generalized performance improvements."

But whether Broadwell will be good or bad or yawn-generating in the next round of iMacs will all depend on Apple's implementation in hardware. Some folks want the current Retina iMac and will buy it now. Good for them. But as for me, I simply remain undecided.

 

[joema2]

I never said "biggest." I merely said Broadwell could be worth waiting for.

That was a direct quote from your post.

...But your argument does appear to proclaim, "Broadwell really won't be as great as some think and therefore probably isn't worth waiting for."

I'm not saying Broadwell isn't worth waiting for. I'm just trying to give a balanced perspective in the face of statements like the Broadwell die shrink will allow let Intel "crank up the clock speed noticeably higher than was possible before". There is no basis for Broadwell having a much higher clock speed, as fundamental physics has resulted in a plateau of frequency scaling for some years.

....It's not like we've been stuck at 3.00GHz for the last 5 years.

Frequency scaling has been essentially flat since late last decade. This can be seen in the previously-posted graphs. Everyone who works in the CPU engineering community knows this -- there is absolutely no debate on it. Picking specific versions of CPUs to examine doesn't change this reality.

How does this affect potential buyers of a new iMac? Very simple: don't expect a much faster clock rate on a Broadwell i7, when the Haswell i7 is already running at 4Ghz.

The main *potential* benefit is increased core count but as you indicated this is limited by thermal and power issues. The severity of this problem has been understood for years in the academic community. In 2011, this was discussed in the pivotal paper "Dark Silicon and the End of MultiCore Scaling": ftp://ftp.cs.utexas.edu/pub/dburger/papers/ISCA11.pdf

 

[ErikGrim]

I'd recommend the base unit. Get a deal at best buy. Plan on selling it in a couple of years and by then you have more options such as 5k monitors, better iMacs (that can be used as a monitor as well), etc.

You're buying the retina iMac for it's screen for the short term, not killer performance, and certainly not 5 years into the future. An i5 and 290x will get you by. Don't sink more money into this than you need to right now in order to satisfy your retina wants.

You'll take a hit with selling. But you're already thinking of blowing 500 on upgrades that you most likely won't even take advantage of.

Sorry, but that logic just doesn’t follow. A high end iMac will hold its resell value far better than a base model in the short AND long term. Especially do not estimate the psychological leap 4Ghz will have over 3.5 two to three years in the future in a buyer’s mind.

I build in a selling price of at least 50% into my computers after FOUR years. Never failed so far.

 

[JDW]

That was a direct quote from your post.

I stand corrected on my used of the term "biggest." My apologies.

However...

I used that term within the context of my original argument that Broadwell would yield the biggest performance leap for the next-gen iMacs with the understanding of Apple's board design. If you've read articles about the logic board design of the 5K iMac versus the 2013 iMac, most are saying the 5K iMac's board design is "largely unchanged" from the 2013 iMac. They are saying the new iMac is basically new in terms of its screen alone. As such, it has been my opinion that Broadwell would then be the biggest change to Apple's logic board implementation to differentiate it from the 2013 board design, hopefully in terms of better "noticeable" performance too.

You opinion, in short form, are rooted in these quotes:

'People should not expect that Broadwell will be the "the biggest performance leap".'

And:

"How does this affect potential buyers of a new iMac? Very simple: don't expect a much faster clock rate on a Broadwell i7, when the Haswell i7 is already running at 4Ghz."


You are arguing that a new iMac isn't necessarily worth waiting for. I understand your arguments, but I still remained unconvinced that waiting for Broadwell wouldn't benefit me. I once bought a Mac IIvx. Since then, I've become a bit more patient, avoiding impulse buys. The Retina display is compelling, but should I buy right now? I am not yet convinced I should. But by all means, if you feel Apple has nothing up their sleeve in terms of great new compelling features in the next-gen iMacs, please further convince me to buy a 5K iMac now!

(Thanks for your opinion. Although I've been arguing with you, I've been doing so in part to convince myself of what to do.)

 

[JDW]

Hmmm...

https://forums.macrumors.com/threads/1804923/

More and more BROADWELL is looking like the next MacIIvx.

Wait for SKYLAKE or buy the 5K Haswell iMac now...

Hmmm...

 

[joema2]

....As such, it has been my opinion that Broadwell would then be the biggest change to Apple's logic board implementation to differentiate it from the 2013 board design, hopefully in terms of better "noticeable" performance too...You are arguing that a new iMac isn't necessarily worth waiting for. I understand your arguments, but I still remained unconvinced that waiting for Broadwell wouldn't benefit me. .

I agree there are opportunities to improve overall system performance besides the CPU clock rate. A dramatic example is my Windows machine which uses a 4Ghz i7-875k "Lynnfield" vs my 2013 iMac 27 which uses a 3.5Ghz i7-4771 "Haswell". On benchmarks and various similar real-world tests, the Haswell-powered iMac is faster, and for one specific thing -- H.264 video encoding -- it is over five times faster, courtesy of Quick Sync.

Each new CPU generation improves the Instructions Per Clock efficiency, albeit slowly. Since Haswell is three generations newer than Lynfield, it adds up. This makes the 3.5Ghz Haswell actually faster in real work than the 4Ghz Lynnfield.

With the retina iMac i7, a 4Ghz i7 is available for the 1st time. At first glance this seems like the Ghz race is resuming, but my Lynnfield-powered Windows machine was made in 2009, and it's running at 4Ghz, also.

While it's great to see a 4Ghz iMac, it is very unlikely further significant CPU clock speedups will happen. This is for two reason: (1) The thermal/power issues already discussed, and (2) The diminishing returns of a given clock speedup. IOW Going from 3 to 4Ghz was a 33% increase. To obtain 33% from 4Ghz would require 5.3Ghz, which is very unlikely.

For comparison the IBM zEC12 mainframe microprocessor runs at 5.5Ghz, but it consumes 300 watts and requires water cooling: https://en.wikipedia.org/wiki/IBM_zEC12_(microprocessor)

...You are arguing that a new iMac isn't necessarily worth waiting for. I understand your arguments, but I still remained unconvinced that waiting for Broadwell wouldn't benefit me...

Sorry if I gave that impression. In general it's always good to get the latest generation. For most (not all) users on top-spec 2013 iMac 27s, I don't see a major advantage vs a top-spec retina iMac from a CPU, GPU, or I/O standpoint. The further back you go, the greater the incentive to upgrade.

This also varies based on specific features. If someone is on a 2011 iMac with a HDD, the I/O performance increase of Fusion Drive or SSD would be large. Likewise someone doing video editing could see a huge performance increase from Quick Sync, which only became available with Sandy Bridge CPUs in the 2011 iMac 27.

Even though Broadwell is nominally a "die shrink", Intel is departing from their normal policy of no micro-architectural changes on die shrinks. Broadwell will have some tweaks that will improve performance a bit at the same clock rate. However this will probably be in the low single digits, %-wise.

Even though I'm a professional video editor I am currently happy with my top-spec 2013 iMac 27. However my co-workers will likely get the top-spec retina iMac since they are on older machines. I will probably get a 2015 retina iMac, not because I don't think the 2014 version is good, but because I won't need it until then. Thanks for the polite discussion.

 

[santaliqueur]

I'd recommend the base unit. Get a deal at best buy. Plan on selling it in a couple of years and by then you have more options such as 5k monitors, better iMacs (that can be used as a monitor as well), etc.

You're buying the retina iMac for it's screen for the short term, not killer performance, and certainly not 5 years into the future. An i5 and 290x will get you by. Don't sink more money into this than you need to right now in order to satisfy your retina wants.

You'll take a hit with selling. But you're already thinking of blowing 500 on upgrades that you most likely won't even take advantage of.

The thing you recommend does not work for everyone. I have a late 2009 iMac with an i7 2.8GHz. I maxed out the ram, and put in a 1TB SSD. I've had this computer for 5 years, and I could probably use it for another 5. I'm going to buy a 5k iMac because I want one, not because I need one. Your advice of "buy a base model because it's not that great and buy another computer in a couple years" advice is not universal advice that applies to everyone.

 

[5iMacs]

The thing you recommend does not work for everyone. I have a late 2009 iMac with an i7 2.8GHz. I maxed out the ram, and put in a 1TB SSD. I've had this computer for 5 years, and I could probably use it for another 5. I'm going to buy a 5k iMac because I want one, not because I need one. Your advice of "buy a base model because it's not that great and buy another computer in a couple years" advice is not universal advice that applies to everyone.

I agree there is no universal advice, and certainly going through the trouble of selling computers every 2-3 years is not big fun. Where this argument works for me is if you're the sort of user that is going to be generally satisfied with the performance of their computer after >3 years, then why would it make a difference whether you purchased a small CPU upgrade at the outset? Your computer is still slow (relative to current models) either way at that point.

I'm not trying to give advice here but it is a valid point of view I think.

 

[sharon22]

Umm......
"He explained that some photo editing software vendors are beginning to program their apps to use the GPU"

I would have *immediately* said, "Sir/Ma'am, um, WHICH vendors."

I absolutely HATE statements that are made / pulled out of a hat without being backed up.

Now, if the salesperson rattled off some vendors and I could verify that, then by golly, that is interesting.

Now, I'm not "calling bullish*t," because the lovely salesman could have been absolutely correct, but I sure want information like that BACKED UP.

I'd want to know WHAT vendors, and also what he/she means by "beginning."

"Beginning," as in, "starting 10 years ago," or, "beginning," as in "starting last week....," or, "beginning," as in "starting the christmas season with the new games...." or WHAT.

I'm not trying to be mary-contrary, I just want people to make INFORMED decisions.

K?

 

[rainydays]

Umm......
"He explained that some photo editing software vendors are beginning to program their apps to use the GPU"

I would have *immediately* said, "Sir/Ma'am, um, WHICH vendors."

I absolutely HATE statements that are made / pulled out of a hat without being backed up.

True. It's not like every app out there is being optimised to use the GPU. Even in pro audio apps the GPU isn't all that useful to developers due to its nature.
If the apps you are using doesn't benefit much from it then it's irrelevant. You can save some money and have a cooler running iMac.

 

[joema2]

Umm......
"He explained that some photo editing software vendors are beginning to program their apps to use the GPU"...I would have *immediately* said, "Sir/Ma'am, um, WHICH vendors."...

GPU-accelerated effects in Photoshop CS6 and earlier:

http://helpx.adobe.com/photoshop/kb/photoshop-cs6-gpu-faq.html

Further GPU-enhanced features added in Photoshop CC:

http://helpx.adobe.com/photoshop/kb/photoshop-cs6-gpu-faq1.html

That said, I don't think Lightroom ver 5 uses any kind of GPU acceleration.

Premiere Pro and FCP X make heavy use of GPU acceleration.

 

[Coufu]

Wait so I have my riMac processing (hasn't shipped yet) configured with a M295X. Should I cancel and downgrade the GPU? I'm so confused, because I heard people with the M290X had problems with mission control lag so I upgraded it. So confusing lol what should I do?!

 

[icemantx]

Wait so I have my riMac processing (hasn't shipped yet) configured with a M295X. Should I cancel and downgrade the GPU? I'm so confused, because I heard people with the M290X had problems with mission control lag so I upgraded it. So confusing lol what should I do?!

I think overall the M295x is a better GPU than the M290x and is not a bad purchase. However, from what I have seen in reviews and specifically from barefeats, it is only in specific cases where you notice an improvement from the upgraded GPU. For me, I am coming from an early 2009 iMac when I upgrade this year to the base model Retina plus 3TB Fusion, this will be way better than what I have right now. It would always be nice to have the top of the line for everything, but for me since I am not a big gamer and do not use any apps that specifically use the GPU acceleration, the M295x is overkill.

I am not a big believer in future proofing as in 5 years, the benefits of the 295x over the 290x will be negligible compared to future technology.

 

[sharon22]

Wait so I have my riMac processing (hasn't shipped yet) configured with a M295X. Should I cancel and downgrade the GPU? I'm so confused, because I heard people with the M290X had problems with mission control lag so I upgraded it. So confusing lol what should I do?!

OMG, please don't miss my point.... my point was not to be "sold" on something just because some salesman pulls statements out of a hat (not that Mr./Mrs. Apple Salesman did that).

If you ARE ALREADY GETTING a Retina iMac, then DEFINITELY "go all in!" Get the 4.0Ghz processor upgrade, AND, most importantly, get the FASTEST GPU available!

Because for all those millions of Retina Pixels, you will WANT processing power!

If I won the lottery, I would get the Retina iMac FOR THE SOLE PURPOSE of being able to get the cool 4ghz CPU, and the top-of-the-line GPU.

Otherwise, it's like getting a Ferrari, with the cheap nylon seats...

 

[rainydays]

If you ARE ALREADY GETTING a Retina iMac, then DEFINITELY "go all in!" Get the 4.0Ghz processor upgrade, AND, most importantly, get the FASTEST GPU available!

Because for all those millions of Retina Pixels, you will WANT processing power!

If I won the lottery, I would get the Retina iMac FOR THE SOLE PURPOSE of being able to get the cool 4ghz CPU, and the top-of-the-line GPU.

They make them with cool i7s as well? I only thought they came with the hot ones.

It's so easy to say "go all in" when it's someone else's money. What if you don't need that power? Then it's a complete waste of money that could have gone towards something much more rewarding.
Why get a Ferrari that can do 240mph instead of one that can do 225mph when you're only cruising around at 56mph? You still get the freaking leather seats!

 

[sharon22]

It's so easy to say "go all in" when it's someone else's money.

LOL - I know I know! I almost suggested they get one of those new Apple watches, too! (The Limited Edition, of course!) And take the family out to a nice dinner, too, to celebrate!

 

[tabarus]

How loud is the i7 with the 295X with no CPU load ?
How loud will it be when I run logic pro x lets say with 50% CPU ?

How does the i7 with a 290x compare noise wise? please

 

[vir3l]

just gave my i7/m295x back and got a 2013 model.

without cpu load, the i7/m295x is 35 db while gaming wow, with max. fan speed of 2700 rpm (avg. 2500)

idle it's not audible and 1200 rpm. only cpu load (handbrake) without gpu sees even higher fan loads of max and avg 2700 rpm with 38 db avg.

can't say about logic pro. but 50% cpu load should scale. low/medium gpu load however, and that's the reason I gave mine back, will make the m295x go very hot and fans go crazy.

will get a retina imac once apple has redesigned their heat management and once content is available. currently browsing the web, watch full hd netflix etc. is just not that fun as contents are made for 1080p.

 

[inhalexhale1]

just gave my i7/m295x back and got a 2013 model.

without cpu load, the i7/m295x is 35 db while gaming wow, with max. fan speed of 2700 rpm (avg. 2500)

idle it's not audible and 1200 rpm. only cpu load (handbrake) without gpu sees even higher fan loads of max and avg 2700 rpm with 38 db avg.

can't say about logic pro. but 50% cpu load should scale. low/medium gpu load however, and that's the reason I gave mine back, will make the m295x go very hot and fans go crazy.

will get a retina imac once apple has redesigned their heat management and once content is available. currently browsing the web, watch full hd netflix etc. is just not that fun as contents are made for 1080p.

I think that was a good move. The 780m is about the same as the m295x anyway. The only reason to buy the retina model is for the screen. The stuff under the hood is about the same as the 2013 model.

 

[Pelican Boy]

sure there's more threads on this but i haven't seen any true answer anyways i was curious to know i'm planning on buying a new 5k iMac with 4ghz 1tb fushion drive and as far as graphics card not sure however i'm not really a gamer when it comes to a mac but i wanted to know is if i upgrade to the M295X would i see an increase for better speeds and graphics for movies and apps or is it just for games? not sure if it's worth the $250 upgrade? thanks in advance.

I've had my Retina iMac for 3 weeks now, i7 processor, 16gb ram, 500ssd & M290x.

I don't use my mac for gaming at all, just all graphics work using Photoshop, Illustrator, Dreamweaver, InDesign etc. The speed is lighting fast, opening up images in Photoshop and applying filters to large files is fast, having all applications open at once and the fan doesn't even come on. For me, the flash storage was the thing I really wanted as I went into the Apple store and tested machines with Fusion drive and Flash storage, all the applications open up so much quicker with flash storage.

If you were doing gaming then probably the M295x is the way to go - I use my PS4 for gaming

 

[tabarus]

How loud does the 780m get when maxing it out ?

I dont going to play any games on a mac either, I just like to make music with it.
Currently beside my Mac I have a PC with a GTX780ti and it is even in idle 34dB and gets even louder under load. And that at 1920 x 1200. I bet it would get very hot on 5k as well.