Rumour: NVIDIA GK104 Specifications
German website 3D Center has compiled what are allegedly the tentative specifications for NVIDIA's upcoming GK104 GPU.
Needless to say, such reports should be taken with fair amounts of salt. However, 3D Center's previous such compilation for Tahiti turned out to be fairly accurate.
Kepler introduces a radical new architecture but the overall structure may be somewhat similar to Fermi. GK104 features 4 overall Graphics Processing Clusters (GPC) – twice that of GF114. Each GPC has 4 SMs – same as GF114. However, each SM now consists of 96 SP or CUDA cores – again twice that of GF114. Each SM features 8 TMU. The end resut is 16 SMs, 1536 SP and 128 TMU. GK104 continues to feature 32 ROP and 256-bit memory interface like GF114.
The core clock is expected to be 950 MHz for the top bin, slightly higher than HD 7970. As previously rumoured, the hotclock for shaders has been dropped, so the shaders will operate at 950 MHz as well. Of course, the drop in shader clocks is compensated by massively increasing shader count – a similar strategy to AMD. The end result is 1536 SP clocked at 950 MHz for 2.9 SP TeraFlops and a 1/6 DP rate of 486 GFlops.
The 256-bit memory interface now uses 2GB GDDR5 and the memory controller is also improved over Fermi, now clocking at 5 GHz GDDR5 for a bandwidth of 160 GB/s. However, this is still massively short of HD 7970's 260 GB/s.
The die size for GK104 is "unofficially estimated" at 340mm2, which is slightly lower than Tahiti's 365mm2. The first GK104 product is due to be released in early Q2 2012.