MODIFIED NV25
Picking a nit, but the XBox GPU is the NV2A, which is a modified NV20. The GeForce4 is an NV25, and the next-gen card due in August is NV30.
as well as 4 simultaneous pixel shaders
But no Z-compression or Z-occlusion! And, that's were the biggest slowdown is in PC graphics today.
Matrox Parhelia is also interesting
Well, for what is rumored to be a $500+ card, I'd hope so.
apparently supporting PS1.4 (only the ATI 8500 does this ATM), which is a very flexible pixel programming language compared to PS1.1 (as implemented by NVidia),
Parhelia - ??? (but it does have vertex shader 2.0 support)
ATI R8500 - PS 1.4
GeForce3/4 - PS 1.3
ATI Radeon - PS 1.0
DX8.0a specs call for PS 1.1 support at least. No one ever used PS1.0 in any app to my knowledge.
The PC market is heating up, but the AGP bus bottleneck is still present nonetheless.
The AGP bus is only a bottleneck for the PC because the CPU are now up in the 3 GHz+ range, and can generate vertex's like mad.
EDIT: Cleaned up some.
XBox CPU to RAM: 0-1.06 GB/s
PC CPU to RAM: 2.7 GB/s
XBox GPU to RAM: 5.34-6.4 GB/s (shared w/ audio and nic, etc.)
PC GPU to GPU RAM: 10.4 GB/s (GeForce4 4600)
Also note that the XBox has 64 MB of shared RAM (CPU and GPU share it).
Most PCs have at least 256 MB of RAM for CPU and the GeForce4 brings 128 MB of RAM for the GPU.
That Max Payne runs faster on PC than XBox is slight proof of this case. You could argue, of course, that as it was designed for the PC, there might be some bias here.
I'm not aware of any highly demanding XBox->PC ports yet, so I guess the final verdict awaits.
At the very least, it is certainly true that the PC that could compete with an XBox certainly costs a LOT more.
Xander F
(Unseen Apostate Directorate of North America - Ohio order)A fanatic is one who, upon losing sight of his goals, redoubles his efforts.
--George Santayana