Nvidia limiting gtx680 compute speed?

Asic transit gloria mundi.
beason
Posts: 50
Joined: Sat Dec 10, 2011 1:58 am
Location: Los Angeles, CA

Nvidia limiting gtx680 compute speed?

Postby beason » Thu Mar 22, 2012 7:42 pm

According to this article:

http://www.tomshardware.com/reviews/gef ... 61-15.html

Nvidia is artificially limiting the compute speed of their consumer graphics cards, including the new GTX680. If so that is extremely disappointing. :x
Time for AMD I guess?

EDIT: or maybe just forget about the GPU altogether
Last edited by beason on Fri Mar 23, 2012 1:44 am, edited 1 time in total.

apaffy
Posts: 46
Joined: Thu Dec 01, 2011 11:00 pm
Location: UK
Contact:

Re: Nvidia limiting gtx680 compute speed?

Postby apaffy » Thu Mar 22, 2012 8:55 pm

Wow unexpected benchmark result. Makes a GTX 580 look a lot more tempting if the price can come down a bit.

stefan
Posts: 44
Joined: Wed Dec 21, 2011 8:57 pm

Re: Nvidia limiting gtx680 compute speed?

Postby stefan » Fri Mar 23, 2012 8:06 am

"Never attribute to malice that which is adequately explained by stupidity" - it might just be a driver SNAFU. When they rush a gamer card to the market, their priority is to excel at gaming benchmarks and the OpenCL compiler will take the back seat. I'd be interested in seeing CUDA or OptiX benchmarks for that card, I would assume NVIDIA puts more emphasis on those than OpenCL.

Dade
Posts: 206
Joined: Fri Dec 02, 2011 8:00 am

Re: Nvidia limiting gtx680 compute speed?

Postby Dade » Fri Mar 23, 2012 8:17 am

beason wrote:Nvidia is artificially limiting the compute speed of their consumer graphics cards, including the new GTX680. If so that is extremely disappointing. :x


Anandtech (and other websites) reports the same kind of results: http://www.anandtech.com/show/5699/nvid ... -review/17

NVIDIA may have designed the 680 just to be able to run the DirectX driver has fast as possible an nothing else. For instance, I have read some news about the size of the 680 register file that could explain why it is extremely slow in running complex GPU computing tasks. It sounds a bit strange considering it is a NVIDIA GPU but there should be another GPU incoming in the next months (i.e. 685 or whatever it is going to be called) and it should be the one for GPU computing (i.e. used in Tesla card, etc.). The die size it is supposed to be nearly 2x the one of 680.

P.S. it is really strange, it looks like we are going back to the days of fixed function hardware :|

stefan
Posts: 44
Joined: Wed Dec 21, 2011 8:57 pm

Re: Nvidia limiting gtx680 compute speed?

Postby stefan » Fri Mar 23, 2012 9:16 am

Dade wrote:P.S. it is really strange, it looks like we are going back to the days of fixed function hardware :|

I blame popular hardware reviews: their verdicts drive card sales, and they all run the same predictable benchmarks. As gfx card vendor that wants to make money, you obviously focus on scoring as high as possible in those benchmarks at the cost of ignoring the rest.

I'd welcome hardware review that not only run standard test but also put hardware through a bunch of surprise cases, the one the vendor did not optimize for. There is already a history of drivers "optimizing" for certain benchmarks.

toxie
Posts: 118
Joined: Mon Nov 28, 2011 12:30 pm
Location: germany
Contact:

Re: Nvidia limiting gtx680 compute speed?

Postby toxie » Fri Mar 23, 2012 1:18 pm

beason wrote:Nvidia is artificially limiting the compute speed of their consumer graphics cards, including the new GTX680. If so that is extremely disappointing. :x


This is DEFINETLY not true. There is no artificial slowdown in the driver/software or hardware crippling involved, its just a change of priorities that was chosen for this line of GPUs (i.e. mainly reducing power consumption drastically while keeping gaming performance at least on-par). For the last generation (Fermi) it was rather the opposite (i.e. huge jump in performance for compute, but moderate jump for games, except for the dx11 features of course).
Better you leave here with your head still full of kitty cats and puppy dogs.

Merax
Posts: 4
Joined: Fri Mar 23, 2012 10:05 pm

Re: Nvidia limiting gtx680 compute speed?

Postby Merax » Fri Mar 23, 2012 10:11 pm

I don't think it's a conspiracy, just changing design goals that resulted in less bandwidth per compute unit.

This article has more details: http://www.realworldtech.com/page.cfm?A ... 2212172023

And you can see from the above Anandtech link that it got faster in tests where computation dominates and slower in tests where memory access dominates.

dr_eck
Posts: 45
Joined: Mon Dec 05, 2011 7:35 pm

Re: Nvidia limiting gtx680 compute speed?

Postby dr_eck » Mon Mar 26, 2012 5:27 pm

I'm confused. According to slide 14 of this presentation http://www.nvidia.com/docs/IO/113297/ISC-Briefing-Sumit-June11-Final.pdf, Kepler is supposed to have almost 3X the DP FLOPS/W of Fermi. Yes, it burns fewer Watts, but I was expecting at least 2X the performance. Is it just the OpenCL compiler? Doesn't Nvidia have a history of poor support for OpenCL? Please tell me that all is well with CUDA.

Dade
Posts: 206
Joined: Fri Dec 02, 2011 8:00 am

Re: Nvidia limiting gtx680 compute speed?

Postby Dade » Tue Mar 27, 2012 8:35 am

dr_eck wrote:I'm confused. According to slide 14 of this presentation http://www.nvidia.com/docs/IO/113297/ISC-Briefing-Sumit-June11-Final.pdf, Kepler is supposed to have almost 3X the DP FLOPS/W of Fermi. Yes, it burns fewer Watts, but I was expecting at least 2X the performance. Is it just the OpenCL compiler? Doesn't Nvidia have a history of poor support for OpenCL? Please tell me that all is well with CUDA.


The slides are probably about the "Big" Kepler, the one with a >500 die size (nearly 2x the size of the 680). The one dedicated to computing tasks. It is supposed to be released in Q4.

NVIDIA seems to go along the path of having a GPU tailored for gaming and one for GPU computing. I'm a bit worried because this could have a bad side effect on prices: GPU computing has always been cheap because it is side product of the gaming market :|

P.S. Nvidia OpenCL support has been quite good until the release of OpenCL 1.1 support with CUDA 4.x back end. I think they have changed their compiler back end with CUDA 4.0 and something has gone really wrong for the OpenCL support (i.e. the performance have been nearly cut in half). It is a long standing problem, that for some unknown reason has not yet been fixed.

spectral
Posts: 382
Joined: Wed Nov 30, 2011 2:27 pm
Contact:

Re: Nvidia limiting gtx680 compute speed?

Postby spectral » Tue Mar 27, 2012 9:36 am

About OpenCL performance,

Have you introduce a bug in the partners.nvidia.com web site ? I'm sure that if you introduce an issue and an example (SLG...) they will give you some feedback and improve it !
Spectral
OMPF 2 global moderator


Return to “GPU”

Who is online

Users browsing this forum: No registered users and 2 guests