GM200/Titan X announced with slow DP

[Picao84]

You know you have been steadily changing your claims from the beginning.  You first came off saying the GM200 would be poor in compute.  That was your claim and i challenged that claim.  The gm200 is actually the most powerful compute graphics cards there are.  You used this term "compute" in just the same fashion as so many of the pro AMD defenders in the time of Tahiti after the gk104 launched.  Just so you know, compute is not DP performance.  The truth is, when people typically talk about a GPUs "compute" performance, they refer to benchmarks and task that do absolutely no double precision calculations at all.  These OpenCL benchmarks, task, bitcoin mining, etc have nothing to do with DP performance and they were always pointed to when someone wanted to show how strong Tahiti was in compute.  Well, turns out that the GM200 is an amassing compute card.

That is totally not true. I never changed any goal posts. My point was always about DP.
See the following post on the old forums, still available ( I tried to copy the link but did not find it):

I was looking for an old thread and then I remembered that many were lost weeks ago.

Anyway, looks like my expectations are not so different from what may happen. No Maxwell HPC chip at all, so GM200 should indeed be a graphics oriented chip...

http://wccftech.com/nvidia-planning-dit ... ving-2017/

The reason behind not deploying Maxwell in Tesla Accelerators is said to be the lack of FP64 Floating Point Units and additional double precision hardware. And the reason behind not including DP FPUs in Maxwell might have to do with the extremely efficient design that NVIDIA was aiming for. This however means that NVIDIA’s upcoming Maxwell core, the GM200 which is the flagship core of the series might just remain the GeForce only offering unlike Kepler which was aimed for the HPC market first with the Titan supercomputer and launched a year later after the arrival of the initial Kepler cores as the GeForce GTX Titan.

Since the DP FP64 FPU hardware blocks will be removed from the top-tier cards that are rumored to arrive next year, they will include several more FP32 FPUs to make use of the remaining core space and that means better performance for the GeForce parts since games have little to do with Double precision performance.

GM200 did not have that much space to grow in 28nm, given that GK110 was already huge. Could they make it faster at DP? Probably yes. But how much? Would it be worth it for say 20% more performance? HPC market is very different from graphics market. HPC is sold in massive quantities, not individual cards. No company is going to massively upgrade their system for 20% extra performance. Jumps in performance must be much higher than that. They kinda did that sort of jump with GK210 double chip cards. They choose to optimise an existing chip, GK110, to reduce power consumption heavily in order to offer a bigger jump in performance than a single GM200 could offer. It was a very intelligent move on their part, IMO.

I even said it was a very intelligent move on their part, so take back your claims about AMD bla bla bla.

It is not a GEFORCE only part, but also a QUADRO part
Just not a high end TESLA part.

More information:
http://wccftech.com/nvidia-gm200-based- ... s-compute/

Hmm, 6,07 TFLops single precision versus GK110 and GM204 5,2 TFlops. Not much of a big jump, is it? Then again, for graphics, nVIDIA architectures were always very efficient per TFlop. However, this makes me question things a little bit.. With weak DP performance, I would have expected a larger jump in single precision. Then again, the possible extra TMUs and ROPS (2x the ROPS of GK110!), plus double the cache of GK110 (I've seen a speculation from somewhere else for 3MB, up from GM204 2MB) might have taken quite a bit of the space left vacant by absent FP64 units.

I even said that the rumored performance, 6,07 TFlops was lower than what I was expecting. So no, you cannot say that I expected less Single Precison performance, or that I don't know the difference between them!!

Maybe you just didnt know what you were talking about or maybe you are changing the goal post.  Either way, there is an issue here and you were not entirely correct in your original claims.

I was correct in my original claims. Looks like you just have poor memory!

Anyway, i have another question for you.  I dont care to get into your debate with gstanford, but there is another problem among your claims.  The gk110 titan did not have this static DP performance that was directly tied to the HW layout.  It doesnt work like you claim at all.  Actually, out of the box you only get something like 1/24th the DP rate.  But you say this is hardwired to the HW layout and this is where your claims get busted.  The titan will not run at 1/3rd DP rate unless you toggle it on through the control panel.  It is a software switch in implemented through driver.  With it off, the Gk110 has the same DP rate as the Gk104.  Toggle it on and it goes to a 1/3 DP rate.

http://hexus.net/tech/reviews/graphics/5...-overview/

This fact is further substantiated by the knowledge that, just like Tesla K20X, TITAN can run double-precision compute at 1/3rd of single-precision speeds, leading to over 1TFLOPS DP throughput. However, being a gamer's card at heart, TITAN's DP rate is set to 1/24th of SP, just like GTX 680, as no games use double-precision calculations. The full 1/3rd ratio can be set via the control panel, yet doing so forces the GPU's clocks down. And no gamer wants that, right?

   

So i guess the GK110 has a shape shifting SMMs or gstan knows something about what he is talking about.  

I am not saying that the gm200 is capable of a higher DP rate, i actually accepted the fact that i was wrong.  I am just saying that you may not know as much as you think about the what nvidia disables DP.  If we look at the gk110, it is obvious that Gstan is correct in suggesting the clock rate goes up.   I am actually glad he was willing to add some valuable information to the discussion.  

No it is up to you to figure out why Nvidia has limited the Gm200 to the same DP rate as the gm204. Cause you both cant be right

My debate with Gstandford IS about the physical limitation on GM200, something that he continues to say its not true! I never said that GK110 on GeForce GTX780Ti was not artificially limited or hardwired (when I said they were fused, I was leading him into a trap.. from the moment he says it is software based he had to understand that if GM200 does not have more than 4 FP64 per SM... he had to understand GM200 is not artificially limited - guess he didn't connect the dots). Of course it is! I even showed the difference between them in active cores (960 vs 90). What you don't seem to understand is that the DP rate is not some internal clock. Its related to the amount of enabled FP64 units (software or otherwise its irrelevant, if the units are not there, there is nothing you can do). Gstanford seems to believe that nVIDIA can, if they want, enable DP rates higher than 1:32 on GM200. They cant! This conversation is all around that. Its silly!

Honestly, I'm out of this forum. There is a pack mentality here that if someone does not share the same vision, they are hunted and accused, directly or indirectly, of being pro AMD. This forum lacks rationality and free thinking. It is even worse than other places you like to bad name. At least on Beyond 3D its possible to have educated discussions and really learn with other people. I have no idea what BTR is, and I certainly started to dislike and distrust Appopin, but you guys... are not any better. Just look at yourselves in the mirror. Your self image might not be who you think you are. Over and out.