Some specs from a leaked slide
| X720 | X360 | Thoughts |
|---|---|---|
| 32nm SOI | 90nm then 65nm now 45nm | Runs cooler |
| 4 OoO cores | 3 in-order cores | More cores, more efficient |
| 4 SMT per core | 2 SMT per core | More efficiency |
| 3.2GHz max in Turbocore mode | 3.2GHz | Same but chip could do more per clock |
| 512 KiB L2 cache per core | 1024 KiB L2 total | More in total, what about snooping? |
| 4 enhanced VMX128 cores | 3 enhanced VMX128 cores | More is better |
| 80MiB EDRAM | 10MiB EDRAM | X720 can support 10 32bit 1080p rendertargets This allows for some FAT gbuffers and Stereo 1080p |
| EDRAM accessible by CPU, VMX and GPU | EDRAM only accessible by GPU | This is a game-changer! Now this ultra-high-speed memory is accessible for general purpose (CPU) and stream processing (VMX) it opens up a whole new world of possibilities |
| Bluray Hardware Decoder | No Bluray anything | Bluray makes sense |
| DX11.1 | DX9 + extensions | All the DX11 goodies plus native Stereo support and DirectCompute … |
In general this is just an improved version of the X360 chip. The really exciting thing is the “80MiB EDRAM shared with the GPU” as that could lead to all-new techniques that are unique to the XBOX 720.
The really exciting thing for XBOX 720 is the combination of Kinect2 with 1080p stereo … think about reaching out and touching virtual objects floating around you … actually punching a game character in the face etc.
