blastingcap
Diamond Member
http://semiaccurate.com/2012/02/01/physics-hardware-makes-keplergk104-fast/
If I didn't post this, someone else would have, so let's discuss it if there is interest.
Edit to add: personally I found this to be the most interesting part (about GK104):
"The architecture itself is very different from Fermi, SemiAccurate’s sources point to a near 3TF card with a 256-bit memory bus. Kepler is said to have a very different shader architecture from Fermi, going to much more AMD-like units, caches optimised for physics/computation, and clocks said to be close to the Cayman/Tahiti chips. The initial target floating among the informed is in the 900-1000MHz range. Rumours have it running anywhere from about 800MHz in early silicon to 1.1+GHz later on, with early stepping being not far off later ones. Contrary to some floating rumours, yields are not a problem for either GK104 or TSMC’s 28nm process in general."
Then
"In the same way that AMD’s Fusion chips count GPU FLOPS the same way they do CPU FLOPS in some marketing materials, Kepler’s 3TF won’t measure up close to AMD’s 3TF parts. Benchmarks for GK104 shown to SemiAccurate have the card running about 10-20% slower than Tahiti. On games that both heavily use physics related number crunching and have the code paths to do so on Kepler hardware, performance should seem to be well above what is expected from a generic 3TF card. That brings up the fundamental question of whether the card is really performing to that level?"
Then he goes on to talk about how GK104 is likely to have variable performance depending on whether or not the game uses PhysX (software OR hardware accelerated physics):
"All of the benchmark numbers shown by Nvidia, and later to SemiAccurate, were overwhelmingly positive. How overwhelmingly positive? Far faster than an AMD HD7970/Tahiti for a chip with far less die area and power use, and it blew an overclocked 580GTX out of the water by unbelievable margins. That is why we wrote this article. Before you take that as a backpedal, we still think those numbers are real, the card will achieve that level of performance in the real world on some programs.
The problem for Nvidia is that once you venture outside of that narrow list of tailored programs, performance is likely to fall off a cliff, with peaky performance the likes of which haven’t been seen in a long time. On some games, GK104 will handily trounce a 7970, on others, it will probably lose to a Pitcairn. Does this mean it won’t actually do what is promised? No, it will. Is this a problem? Depends on how far review sites dare to step outside of the ‘recommenced’ list of games to benchmark in the reviewers guide."
I guess all those people thinking Charlie stopped hating on Nvidia were wrong, he still hates them. Haha.
If I didn't post this, someone else would have, so let's discuss it if there is interest.
Edit to add: personally I found this to be the most interesting part (about GK104):
"The architecture itself is very different from Fermi, SemiAccurate’s sources point to a near 3TF card with a 256-bit memory bus. Kepler is said to have a very different shader architecture from Fermi, going to much more AMD-like units, caches optimised for physics/computation, and clocks said to be close to the Cayman/Tahiti chips. The initial target floating among the informed is in the 900-1000MHz range. Rumours have it running anywhere from about 800MHz in early silicon to 1.1+GHz later on, with early stepping being not far off later ones. Contrary to some floating rumours, yields are not a problem for either GK104 or TSMC’s 28nm process in general."
Then
"In the same way that AMD’s Fusion chips count GPU FLOPS the same way they do CPU FLOPS in some marketing materials, Kepler’s 3TF won’t measure up close to AMD’s 3TF parts. Benchmarks for GK104 shown to SemiAccurate have the card running about 10-20% slower than Tahiti. On games that both heavily use physics related number crunching and have the code paths to do so on Kepler hardware, performance should seem to be well above what is expected from a generic 3TF card. That brings up the fundamental question of whether the card is really performing to that level?"
Then he goes on to talk about how GK104 is likely to have variable performance depending on whether or not the game uses PhysX (software OR hardware accelerated physics):
"All of the benchmark numbers shown by Nvidia, and later to SemiAccurate, were overwhelmingly positive. How overwhelmingly positive? Far faster than an AMD HD7970/Tahiti for a chip with far less die area and power use, and it blew an overclocked 580GTX out of the water by unbelievable margins. That is why we wrote this article. Before you take that as a backpedal, we still think those numbers are real, the card will achieve that level of performance in the real world on some programs.
The problem for Nvidia is that once you venture outside of that narrow list of tailored programs, performance is likely to fall off a cliff, with peaky performance the likes of which haven’t been seen in a long time. On some games, GK104 will handily trounce a 7970, on others, it will probably lose to a Pitcairn. Does this mean it won’t actually do what is promised? No, it will. Is this a problem? Depends on how far review sites dare to step outside of the ‘recommenced’ list of games to benchmark in the reviewers guide."
I guess all those people thinking Charlie stopped hating on Nvidia were wrong, he still hates them. Haha.
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