03-19-2015, 09:06 AM
(03-17-2015, 11:30 PM)Picao84 Wrote: Like I speculated in the old forum, Big Maxwell, unlike Big Kepler/Fermi, is not strong in DP: only 0,2 TFlops.
One more for the record, following my speculation that Maxwell would be most if not all done in 28nm, several months before the release of GM204. As usual, I was faced at the time with some fierce opposition to this idea, never mind how many arguments and facts I thrown at it.
On a side note, the keynote is very very interesting. Lots of information about Pascal and performance estimates: 10x faster than Maxwell!!
http://www.ustream.tv/channel/gpu-techno...rence-2015
Pico84, i was one of the people that thought that the gm200 would have a higher DP ratio that the gm204. I even suggested maybe the gk210 was a result of a special contract that needed the specific changes that the chip offered over the gk110.
I really did expect a higher DP ratio. I wasnt so sure the DP ratio would be as high as kepler's but i really felt that the full gm200 would still best the gk110 in DP, even if by small tad. I fully expected it to better the gk110 in DP performance, at the very least.
So my expectations were wrong.
YOU WIN!!!!
If that makes you feel better, I have no problems admitting my imagined version of the gm200 was wrong on my personal DP performance expectations of the gm200. But..........
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.
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.
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/
Quote: 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