A few weeks ago, a website called VGleaks posted up what it claimed were the CPU hardware specifications for the next Xbox console from Microsoft. Now that same website has done it again and posted up what it claims will the hardware behind the console"s GPU.
The information claims that the GPU will have a clock speed of 800 MHz. The article lists some of the other GPU hardware stats:
Compute
Shader cores - 12
Instruction issue rate - 12 SCs * 4 SIMDs * 16 threads/clock = 768 ops/clock
FLOPs 768 ops/clock * (1 mul + 1 add) * 800 MHz = 1.2 TFLOPs
Interpolation ( 768 ops/clock / 2 ops ) * 800 MHz = 307.2 Gfloat/sec
Geometry
Triangle rate 2 tri/clock * 800 MHz = 1.6 Gtri/sec
Vertex rate 2 vert/clock * 800 MHz = 1.6 Gvert/sec
Vertex/buffer fetch rate (4 bytes) 4 elements/clock * 12 SCs * 800 MHz = 38.4 Gelement/sec
Vertex/Buffer data rate from cache 38.4 Gelements/sec * 4 bytes = 153.6 GB/sec
Memory
Peak throughput from main RAM 68 GB/sec
Peak throughput from ESRAM 128 bytes/clock * 800 MHz = 102.4 GB/sec
ESRAM size 32 MB
GSM size 64 KB
LSM size 12 SCs * 64 KB = 768 KB
L2 cache size 4 x 128 KB = 512 KB (shared)
Texture
Bilinear fetch rate (4 bytes) 4 fetches/clock * 12 SCs * 800 MHz = 38.4 Gtexels/sec
Bilinear data rate from cache 38.4 Gtexels/sec * 4 bytes = 153.6 GB/sec
L1 cache size 16 KB/SC * 12 SCs = 192 KB (nonshared)
Output
Color/depth blocks 4
Pixel clear rate 1 8×8 tile/clock * 4 DBs * 800 MHz = 204.8 Gpixel/sec
Pixel hierarchical Z cull rate 1 8×8 tile/clock * 4 DBs * 800 MHz = 204.8 Gpixel/sec
Sample Z cull rate 16 /clock * 4 DBs * 800 MHz = 51.2 Gsample/sec
Pixel emit rate 4 /clock * 4 DBs * 800 MHz = 12.8
Gpixel/sec Pixel resolve rate 4 /clock * 4 DBs * 800 MHz = 12.8 Gpixel/sec
The article claims that, among other things, the GPU has 32 MB of embedded SRAM which it believes will not have some of the restrictions that the current Xbox 360 has with EDRAM. The article also says the GPU has a two stage caching system, along with two types of fetch operation. Each of the GPU"s shader cores reportedly has its own L1 cache, Local Share Memory and scheduler, plus four SIMD units. In terms of antialiasing, the article claims the GPU supports 2x, 4x and 8x MSAA levels.
If you believe the rumors, the next Xbox GPU is based on a fairly high end Radeon chip from AMD. Microsoft is expected to officially announce the console sometime in the first half of 2013, with a launch in the fall of this year. As we reported last week, Sony is planing to hold a press event on February 20th, where it is expected to officially announce the successor to the Playstation 3.
Source: VGleaks | Image viaVGleaks