Rally said:
The best idea would be, to change the bussystem from 128 bit to 256 bit, like in the Geforce 7900 GT. The slow bus with only 22 GB/s is the weakest point in the ps3 architecture. Current PCs have twice the bandwidth.
I don't get why this keeps coming up. I'd have thought people would have got it by now.
The PS3 splits the 256bit bus used in the PC part into 2 x 128 bit bus. One to VRAM, and the other via FlexIO to system memory. The same bandwidth is available in the PS3 (more or less) as in the PC version (7900), but is split down 2 paths.
For a game console this is a big win, as it can render directly from dynamically generated geometry or textures in main memory.
On a PC, any dynamic data that's changing per frame (e.g. Physics objects, Streamed data, Decoded movie frames etc) has to be transferred over the PCI express bus (which is max 4GB/s on the latest x16 version, but more likely 2GB/s or less). This is really slow, and so you can have huge detailed geometry and textures that just sit in VRAM and never change, but as soon as you start wanting to blow stuff up, you have to start moving things over the painfully slow PCIe or worse AGP bus.
The RSX can render this data directly from the main memory using the other half of the 256bit bus that the PC part dedicates completely to VRAM. This obviously is at the cost of bandwidth to VRAM, but this makes alot of sense to do this when you know that alot of your data needs to be changing each frame, as you do in a game.
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