The nVidia GTX 680

[Dirk Broer]

nVidia has a new card, the GTX 680, which they claim is world's fastest card at the moment. But seeing the relevant (for crunchers that is) benchmarks, I'm less than impressed. Why?

The good:
nVidia finally has a card with a decent SINGLE precision performance and as a bonus with a good GFLOP/Watt (in tdp) ratio

3090/195=15.85
The 3,090 is between the performance of the HD 7950 (2867) and the HD 7970 (3789), the 15.85 is an unprecedented good value for nVidia
(their previous best performer in the GLOPS per Watt was the GTX 560Ti with a score of 7.43, my GTX 260 does 3.54...)

Compared with the GTX 580 this card has three times the Cuda cores, twice the texture units, but slightly less ROPs. (32 compared to 48)
GPU Core runs at same speed as the shaders now (shaders used to do twice the core speed with nVidia's earlier designs) while memory runs at an insane 6000 Mhz.

The bad:
For some reason some marketing guru at nVidia decided to cut the DOUBLE precision performance to a shocking 1/24th of the single precision performance. Fermi had 1/8 (not all), older designs did with 1/12. As a comparision: Ati/AMD cards used to have 1/4 or 1/5 ratios.

As a result of this way of pushing their Quadro and Tesla (who have the ratio, using the same basic chip, at 1/2) the GTX 680 has a double precision performance of a meagre 129 GFLOP, about the level of a HD 4830 (which scores 147.2 GFLOP DP actually)
The GFLOP/Watt DP thus ends with a dissapointing 0.66

The HD 7750, a mid-range AMD card, does 819 GFLOP single precision, but due to a change in AMD strategy cutting DP performance to 1/16th of SP, manages 51.2 GFLOP double precision, doing so at a mere 55 Watt,
giving a score of 14.89 GFLOP/Watt SP and 0.93 GFLOP/Watt DP. I already declared this card a bit prematurely the new king of budget crunching, but that title remains with the HD 4770. The cutting of DP to 1/16th of SP is for both Cape Verde (77xx) and Pitcairn (78xx) GPUs, the Tahiti (79xx) gets 1/4 and remains a good cruncher both SP and DP

The HD 7970, the rival to the GTX 680, does 3789 GFLOP single precision and 947 GFLOP double precision, this at a tdp of 230 Watt.
While that wattage might frighten you -and your wallet-, it means 16.47 GFLOP/Watt SP and 4.12 GFLOP/Watt DP, surely more attractive figures than nVidia's flagship.

[Nflight]

God Awful, at least MAD listens to its core client users!

[Dirk Broer]

So you use mad processors? And mad video cards? Or am I mad? (yes is no option)

[AMDave]

It's from hanging out with MADave too often :P

search yields 11 results on this forum

ed - I promised a long long time ago and signed in blood not to ever mention ever the ode to green ever again. But I couldn't pass up this opportunity. My fingers were crossed. Mwahahahahahaaaa. - ed

[Nflight]

Sorry I got AMDave and MAD letters confused, pleased forgive me. I meant to say AMD. You see Dave rubs off on me more then you can imagine!

[AMDave]

Holy cow man! He could have some really weird and furtive imagination! >> I think he means more like in a transfer-tattoo kind of way. Yup yup.

Yeah. Letters are confusing. They don't have reply buttons and there's no un-delete after you put them in the waste bin. Totally sucks.
Plus what's up with this "insufficient postage" garbage???
I'm going back to email. It's got much better emoticons

[Dirk Broer]

[Jason1478963]

This is very good information to have out there with more and more GPU projects coming up. Thanks for the time and effort to put that information together

[Dirk Broer]

I am at the verge of replacing my HD 3870 (especially re-launched for Moo! challenges) with a HD 7750
Double the performance at half the cost, who wouldn't want that?

The old 200 Watt GTX 260 will be replaced with the only slightly less powerfull, but far cheaper running 115 Watt GTX 550,
while the old 50 Watt GT 9500 will be replaced in the future with an equivalent product in nVidia's new 600-series,
offering at least the same performance for a lower running cost or else more performance at the same cost.
(but if Einstein and Seti get an official AMD GPU client, nVidia has seen the last of me!)

[Dirk Broer]

Yikes, nVidia has an answer to AMD latest cards!
The answer is the GTX 690. This double-GPU monster packs 5622 GFLOP Single Precision performance (and 234 GFLOP Double Precision) for the cost of 300 Watt of wallpower, thereby reaching the -for nVidia- unprecedented high value of 18.74 GFLOP SP/Watt tdp, DP sticking at a mere .78
The 18.74 is quite good though, and 5622 GFLOP Single Precision is quite good as well, making this card the most attractive nVidia card of the moment, followed by the GTX 680, GTX 670 and .....the DDR3 Kepler edition of the OEM GT 640. Watch for this card on eBay and the likes!
There are three GT 640ies, all OEM. One is based on a GF116 Fermi GPU and only has 144 shaders. Avoid it! The other two are based upon a 384 shader GK107 Kepler GPU and come in DDR3 and DDR5 editions. The DDR3 version only consumes 50 Watt, the DDR5 version does 75 Watt, making the DDR3 model quite interesting as it reaches a quite respectable 12.24 GFLOP SP/Watt tdp. Another potentially interesting card could be the upcoming GTX 660, but I've yet to see the amount of GFLOPs it does for its tdp of 150 Watt.