New Mac Pro GPU speculation

JDG1980

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Jul 18, 2013
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The first cylindrical Mac Pro was announced in June 2013 and released near the end of that year. With the system starting to show its age, there is a good chance we'll see a refresh announced sometime this year.

On the CPU side, the refresh path is fairly straightforward: just replace Ivy Bridge-E with Haswell-E. The GPU side is less clear. While Maxwell would seem to be the obvious selection, this presents some issues; Nvidia has generally been less willing than AMD to create semi-custom solutions of the sort that Apple needs, and equally important, Maxwell simply can't provide reasonable performance in Double Precision computing. The latter is not important for most gamers, but the Mac Pro is a GPGPU-focused system designed for artistic, technical, and scientific tasks. To put this in perspective, GM200 Titan X has lower DP GFLOPS (48) than the lowly Pitcairn (160). Sure, Apple could downplay this in their marketing, and people who care mostly about photo/video editing won't mind. But they will lose at least some sales. Focusing on CUDA isn't going to happen; Apple doesn't want to promote third-party proprietary solutions (their support for OpenCL is not an aberration; look at their position on Flash).

It's possible they could use Kepler; a GK110 (tweaked to fit in the Mac Pro's thermal envelope) with full 1/3 DP performance would beat the current flagship D700 Tahiti in almost everything. But is Apple really going to want cards that are obsolete the moment they're produced, especially since Nvidia guards their markups jealously? That's assuming Nvidia would even produce a custom SKU, which they might not.

I think the strongest possibility is that the next Mac Pro continues to use AMD GPUs. But the GCN 1.0 products in the current generation (FirePro D300, D500, and D700 - Pitcairn, Tahiti, and Tahiti respectively) are no longer good enough for a high-end workstation. In fact, none of AMD's current lineup really fits - with one exception. We have to look to what AMD will be releasing in June. In fact, I wouldn't be surprised if Apple's involvement is the primary reason for AMD's extreme secrecy this time out. Apple is very insistent on zero leaks, and they demand that their suppliers maintain the same policy. If Apple is planning to announce the 2015 Mac Pro in June - two years after the 2013 Mac Pro announcement - then part of the deal might have been that AMD remains tight-lipped until then.

So, what GPUs would be suitable for a 2015 Mac Pro? On the low end, the obvious choice would be to replace Pitcairn with a fully-enabled Tonga. In fact, the Pitcairn->Tonga upgrade was already done once, when AMD replaced the discrete FirePro W7000 with the FirePro W7100 at the same TDP (though the latter was a cut-down Tonga, not full). So the entry-level Mac Pro GPU (let's call it the "FirePro E300") will be Tonga with 2048 shaders, a 256-bit bus, and 4GB of GDDR5 VRAM. This would easily beat the FirePro D300 (Pitcairn) in everything.

On the high end? Well, Hawaii can be ruled out; it runs too hot for the Mac Pro's shared heatsink (even Tahiti stressed that quite a bit when both GPUs were run full blast), and the power requirements are way too much as well. So the next obvious question is whether the upcoming Fiji might fit the bill. Even if the full chip would have too high a power envelope, reducing the shader count and the GPU core clock might be enough to get it to work. I'm going to put my speculation out there: the premium Mac Pro GPU (let's call it the "FirePro E700") will be Fiji with 3584 shaders and 8GB of HBM. (I don't believe the 4GB limit rumors; besides, the Tahiti FirePro D700 had 6GB, so 4GB would be a regression.)

What do you think? Does this sound plausible, or will Apple do something different?
 

RussianSensation

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Sep 5, 2003
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Very good post. One possibility is Apple could add custom Hawaii chips. Since their Tahiti XT cards are underclocked and highly binned, it's possible an enhanced Hawaii with lower clocks could fit the bill. Remember that HD7970 used almost 200W at load but they managed to bin them and underclock them to fit 2 of those into the Mac. I think we can't rule out an enhanced and highly binned Hawaii derivative either. Also, there were a lot of rumours that 8GB HBM1 is possible via dual-link interposer. It's hard to imagine how AMD intends to make an R9 395X2 card limited to only 4GB of VRAM.

Mac Pro won't be revised this year.

Why not? If it's not revised this year, it's a LONG wait for something much better next year. Skylake-E is ways off and mid-range to high-end 14nm/16nm GPUs are probably not due until Q3 2016 at the earliest. That would mean almost a 1.5 year wait according to you.
 
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JDG1980

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Jul 18, 2013
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Mac Pro won't be revised this year.

Source?

...or they could beef up their cooling and use hawaii?

That's easier said than done. It's not a matter of just slapping on a bigger heatsink; the Mac Pro has a unified thermal core, so the whole system would have to be re-engineered, and it might not be possible to fit it within the same small size. There are also restrictive space limitations for the PSU.

I think Apple is going to want to stick to the existing Mac Pro design (perhaps with minor tweaks) for at least one more generation.
 
Feb 19, 2009
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Well if Apple is using Fiji, that would easily explain the delays in volume ramping. Just like all the good Tonga chips went to Apple leaving PC with the crap 285.
 

JDG1980

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Jul 18, 2013
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Very good post. One possibility is Apple could add custom Hawaii chips. Since their Tahiti XT cards are underclocked and highly binned, it's possible an enhanced Hawaii with lower clocks could fit the bill. Remember that HD7970 used almost 200W at load but they managed to bin them and underclock them to fit 2 of those into the Mac. I think we can't rule out an enhanced and highly binned Hawaii derivative either.

Sure, it's conceivable that they could downclock Hawaii enough to shove it in. The FirePro W8100 has a rated TDP of only 188W, which is a heck of a lot lower than the consumer equivalent R9 290. Some of this is binning, and some is lower clocks (824 MHz for FirePro W8100, compared to 947 MHz on the stock R9 290). But Hawaii is considerably less efficient than Tonga; once Hawaii is downclocked enough, the gap between it and Tonga would probably be too small. There would also be other issues like Hawaii having a worse UVD block than Tonga. Going with GCN 1.2+ across the board would make more sense for Apple.
 

dragantoe

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Oct 22, 2012
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It's such a shame Apple had to design such a small case for a professional workstation, it really hinders its practically, which was the pro's only real selling point
 

raghu78

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Aug 23, 2012
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I am pretty confident of Fiji being in the next gen Mac Pro. Haswell-E and Fiji are the most likely combination as Broadwell-E will not be out by Q3 2015 to ramp for a Q4 2015 launch in the Mac Pro.

The current HBM1 chips are 4 Hi - 4 stacked DRAM chips. 8 Hi configs will be coming according to Hynix and they will double the memory per chip and thus per stack.

http://videocardz.com/55259/sk-hynix-shows-off-hbm1-and-hbm2
http://www.hardwareluxx.de/index.ph...8-sk-hynix-zeigt-weitere-details-zu-hbm2.html
gtc2015-skhynix-2.jpg


So we will see 16 GB with 8 HBM stacks. There is a mistake in the HBM slides as Hynix's website clearly says the current 4Hi chips are 8 Gb or 8 Gigabit with 2 Gb per individual DRAM chip. Remember each chip in the 4 Hi stack is connected to two 128 bit channels and thus each channel is connected to 1Gb.

I am sure the next gen flagship Firepros are waiting for 8 Hi HBM1 so as to sport 16 GB configs with 8 HBM stacks which would be perfect as they would hold the line in VRAM capacity against Firepro W9100 which has 16 GB. Obviously performance and power efficiency will be vastly improved in the next gen Firepro due to increased sp count, improved microarchitecture and HBM.

I think there is a high chance that Apple gets first allocation / priority for the Firepro chips and is more of a launch customer for AMD. It will be an amazing achievement for AMD to have Apple endorse the world's fastest HPC graphics card with full double precision support by highlighting it in their marketing for the Mac Pro. btw AMD will have fp64 enabled in Fiji unlike GM200. HBM is going to give AMD a lot of advantages against Nvidia as Nvida have to had make significant sacrifices (gutted fp64) to build a gaming focussed GM200.

We can expect a Q4 2016 launch for the next gen Firepros based on Fiji. The R9 395X2 too might launch in Q4 2016. AMD is in for a busy H2 2016 atleast with their GPU division. :thumbsup:
 
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ShintaiDK

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Apr 22, 2012
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I am pretty confident of Fiji being in the next gen Mac Pro. Haswell-E and Fiji are the most likely combination as Broadwell-E will not be out by Q3 2016 to ramp for a Q4 2016 launch in the Mac Pro.

Not sure where you got your random dates from. Or do you refer to Broadwell-EP?

skylake.jpg


The current HBM1 chips are 4 Hi - 4 stacked DRAM chips. 8 Hi configs will be coming according to Hynix and they will double the memory per chip and thus per stack.

http://videocardz.com/55259/sk-hynix-shows-off-hbm1-and-hbm2
http://www.hardwareluxx.de/index.ph...8-sk-hynix-zeigt-weitere-details-zu-hbm2.html
gtc2015-skhynix-2.jpg


So we will see 16 GB with 8 HBM stacks. There is a mistake in the HBM slides as Hynix's website clearly says the current 4Hi chips are 8 Gb or 8 Gigabit with 2 Gb per individual DRAM chip. Remember each chip in the 4 Hi stack is connected to two 128 bit channels and thus each channel is connected to 1Gb.

I am sure the next gen flagship Firepros are waiting for 8 Hi HBM1 to sport 16 GB configs which would be perfect as they would hold the line in VRAM capacity against Firepro W9100 which has 16 GB. Obviously performance and power efficiency will be vastly improved in the next gen Firepro due to HBM.

I think there is a high chance that Apple gets first allocation / priority for the Firepro chips and is more of a launch customer for AMD. It will be an amazing achievement for AMD to have Apple have the world's fastest HPC graphics card with full double precision support. btw AMD will have fp64 enabled in Fiji unlike GM200. HBM is going to give AMD a lot of advantages against Nvidia as Nvida have to had make significant sacrifices (gutted fp64) to build a gaming focussed GM200.

We can expect a Q4 2016 launch for the next gen Firepros based on Fiji. The R9 395X2 too might launch in Q4 2016. AMD is in for a busy H2 2016 atleast with their GPU division. :thumbsup:

Dont mix marketing slides with reality. Hynix still only sells a 1Gbyte stack that isnt even present on the slide you link. HBM2 will sell from Q2 2016 and quickly replace HBM1 completely.

18f593cf-ca59-4050-8e38-d28fe5d993f3.jpg


It seems Hynix is far from reaching desired densities. Very far.
 
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Glo.

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Apr 25, 2015
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...or they could beef up their cooling and use hawaii?

They don't need to beef up the cooling.

http://forums.macrumors.com/showpost.php?p=20880421&postcount=177

Hawaii stays within 145W of TDP at 850 MHz in stress tests. That is pretty amazing.

Couple that with new, better process, and HBM implementation, and you can get more performance from them with less TDP. And that would mean the information that Cloudfire got, about coming GPUs from AMD, are true...

Im waiting for this new Mac Pro as I've never been waiting for another computer.

4.9 Tflops of SP at 145 TDP. Not bad, not bad at all.
 
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raghu78

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Aug 23, 2012
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Not sure where you got your random dates from. Or do you refer to Broadwell-EP?

actually I meant Broadwell-E will not launch in Q3 2015 for a Q4 2015 launch for Mac Pro.

Dont mix marketing slides with reality. Hynix still only sells a 1Gbyte stack that isnt even present on the slide you link. HBM2 will sell from Q2 2016 and quickly replace HBM1 completely.

That Hynix slide has certain errors but the idea is simple. Hynix has started shipping 8 Gb (1 GB) HBM stacks using four (4) 2 gigabit chips in a 4 Hi config. The higher capacity using 8 Hi HBM stacks will happen in a few months. By stacking 8 DRAM chips of 2 Gigabit capacity, the total DRAM capacity per HBM stack is doubled to 16 Gb (2 GB). Using the dual link interposer featured in R9 390X the total capacity will be 2 x (2 GB x 4 stacks) = 16 GB per graphics card.

I do not expect you to agree as usual. So lets wait for the actual R9 390X launch and the next gen Firepro launch which will most probably happen in Q4 2016.
 

Ranulf

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Jul 18, 2001
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It's such a shame Apple had to design such a small case for a professional workstation, it really hinders its practically, which was the pro's only real selling point

Its Apple, its what they do. It has to be avant garde and trendy. It is a neat proof of concept, an engineering demo and keeps what workstation customers they have stuck in Apple's upgrade cycle.
 

nvgpu

Senior member
Sep 12, 2014
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It is not 1/128, if it was 1/128, Pitcairn would be faster in DP yet it isn't.

72530.png


TITAN X 7.2

67230.png


270X 3.4

DSC_0449_575px.JPG


GTC 2015, 200 GFLOPS DP, it's certainly not 48.
 
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Stuka87

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Dec 10, 2010
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There is no reason a Hawaii would not work is clocked down some. Tests have shown that its TDP drops significantly if you under clock/volt it.

AMD's OpenCL support is significantly better than nVidia's. nVidia only supports 1.2, AMD has supported 2.0 since last year, and 1.2 for several years. Apple will never go the way of CUDA, as they are very much against proprietary libraries that lock them into a single vendor.
 

thesnog

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Apr 26, 2015
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I think Apple will stick with AMD, since they are much more willing to make custom cards and Apply has used them in all their most recent desktops (2013 Mac Pro and Retina iMac). I think its most likely Fiji ends up as the high end option, especially if AMD can make a version with 8 GB of VRAM. The question is how does the rest of the lineup fill out.

The current Mac Pro has 3 tiers (D300, D500 and D700), currently Pitcairn (2 GB) -> Tahiti (cutdown, 4 GB) -> Tahiti (6 GB). Apple likes to use VRAM to distinguish cards as well. There are a couple options here, first: Tahiti (3 GB) -> Tonga (4 GB) -> Fiji (8 GB). Or if Apple decides they only want to only offer new architectures, we could see Tonga (4 GB) -> Fiji (cutdown, 4 GB) -> Fiji (8 GB). This last one has overlapping VRAM sizes, which apple tends not to do. I think it comes down to if Apple thinks all "pros" need 4 GB of VRAM and if they want to use the most up to date GCN in the mac pro.

If Apple did choose NVIDIA, they would probably just pick 3 different versions of maxwell with 3 memory configurations. In this case though they could offer up to 12 GB of VRAM available in the Titan X.

My guess is that the new mac pro comes at WWDC in June with Apple announcing they are supporting new versions of openCL in the next version of OS X that can take advantage of both graphics cards at once. Another thing that may be a factor is Apple trying to get displayport 1.3 and thunderbolt 3 into a new machine so it can make a standalone retina 5k display that only needs a single cable.

Putting out a new version of the Mac Pro in the near future would be a good bridge until Skylake-E is ready in 1.5-2 years and the next gen graphics at a smaller node come out from NVIDIA and AMD.
 

Tuna-Fish

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Why not? If it's not revised this year, it's a LONG wait for something much better next year.

In general, Apple doesn't let component releases dictate their release cycle. They are perfectly happy shipping slightly older stuff until they feel that they want to release again.
 

Glo.

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Apr 25, 2015
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And in 2011 realesed new Macbook Pros 2 days after Intel released their Intel CPUs.
 

dragantoe

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Oct 22, 2012
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keeps what workstation customers they have stuck in Apple's upgrade cycle.

This is an excellent point. Now Apple is forcing their customers to get whole new desktops instead of upgrading them (that statement nauseates me to type), even though I'm sure most professionals (ESPECIALLY the ones I'm with) would much rather just have custom built windows workstations, or worst case, have to build a hackintosh.
 

Enigmoid

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Sep 27, 2012
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In general, Apple doesn't let component releases dictate their release cycle. They are perfectly happy shipping slightly older stuff until they feel that they want to release again.

This

Considering how long the previous mac pro languished I have no problem believing that apple will refresh in more than a year with 14 nm CPUs and GPUs.