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Re: Waiting for 980?
Posted: Tue Sep 16, 2014 1:34 pm
by riggles
I'm a little confused about the 980. From the naming, you'd naturally think it's a 780 replacement, and then wonder why it has less CUDA cores (2048 vs 2304). But if you look at the codename, the 980 is a GM204 chip, which seems to be the successor to the GK104 used in the 770 (1536 CUDA cores), not the GK110 used in the 780. So is the new 970 and 980 basically replacing the 770 with two separate cards, with a 780 replacement turning into something else not yet released?
Edit: I do fear that NVIDIA will try to move those using their GeForce gaming cards for commercial purposes (CUDA rendering) into higher priced cards by lowering the CUDA capabilities of their gaming cards. But I honestly don't know enough about the tech behind GPU architecture to know if that's even possible.
Re: Waiting for 980?
Posted: Tue Sep 16, 2014 3:49 pm
by dsyee
The 980 is a GMXXX chip, so it's based on Maxwell instead of Kepler, which supposedly means you get better performance out of each core.
The GTX cards are already crippled with regard to double-precision performance, aren't they? Fortunately the GPU renderers only need single-precision.
Re: Waiting for 980?
Posted: Tue Sep 16, 2014 7:53 pm
by Seekerfinder
dsyee wrote:The 980 is a GMXXX chip, so it's based on Maxwell instead of Kepler, which supposedly means you get better performance out of each core.
That's the theory. Let's hope it turns out to be the case.
Seeker
Re: Waiting for 980?
Posted: Fri Sep 19, 2014 1:22 am
by riggles
Just looking some more at the specs as they're revealed, and how they compare to existing cards.
Code: Select all
GTX 780: 2304 Cores 4 Teraflops (SP)
GTX Titan: 2688 Cores 4.5 Teraflops (SP)
GTX 780Ti: 2880 Cores 5 Teraflops (SP)
GTX Titan Blk: 2880 Cores 5.1 Teraflops (SP)
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GTX 980: 2048 Cores 5 Teraflops (SP)
Now, I'm not clear on the the relationship between CUDA cores, single precision (SP) floating-point performance, and overall Octane performance. However, we do know that Octane takes advantage of a cards SP performance, not double precision. Also, looking at one of the
Maxwell announcement slides, there's supposed to be a 40% increase in performance per CUDA core over Kepler. Based on my rusty math, a 40% increase would bring the effective Kepler cores of a GTX 980 from 2048 to 2867—very close to that of the 5-Teraflop performing GTX 780Ti. Interesting.
So, by my complete guesstimate and speculation, it's possible this new GTX 980 could end up being as fast as the 780Ti and Titan Black in Octane, but with more memory than the 780Ti, lower power requirements/heat dissipation (165W vs. 250W), and for less money.
How well will Maxwell cards run on Octane? Who knows. But it's
possible that this could be a decent card.
Re: Waiting for 980?
Posted: Fri Sep 19, 2014 6:39 am
by acc24ex
don't forget that the 1024 cores from a 590gtx is around 10% slower than 780Ti with its 20 - which means the number of cuda cores don't mean much, even a 40% increase is still not 100% increase from a 2-3 year old tech, only way to find out is to burn some octane on it
Re: Waiting for 980?
Posted: Fri Sep 19, 2014 7:59 am
by glimpse
riggles wrote:
How well will Maxwell cards run on Octane? Who knows. But it's possible that this could be a decent card.
750 is Maxwell based card test on 7xx naming =)
it delivers around gtx460 performance only consuming 70W =)
Re: Waiting for 980?
Posted: Fri Sep 19, 2014 8:50 am
by suvakas
Re: Waiting for 980?
Posted: Fri Sep 19, 2014 9:22 am
by smicha
970 & 980 are on newegg now, for 330$ & 550$ respectively
Re: Waiting for 980?
Posted: Fri Sep 19, 2014 9:31 am
by FamilyGuy
Don't look on this test. In Octane Render GTX580=GTX780 and in luxmark GTX780 is 32% faster.
Re: Waiting for 980?
Posted: Fri Sep 19, 2014 9:35 am
by smicha
780 is about 2x faster than 580