zarx said:
I wouldm'y have thought that a modern unified programmable pipeline GPU would have much trouble emulating an older GPU, a unified shader should in theory be able to do anything a vertex or pixel shader can. The GPU in the PS3 is basically off the shelf as far as I know so no fancy "smart" EDRAM or anything exotic in the architecture like the 360 does. Not like the PS2's custom GPU and CPU architecture. Tho it's not directly compairableas the GPU would be programed "direct to metal" in the PS3, but all DX10/11 GPUs maintain DX9 compatability even tho unified shaders were a DX10 feature. I guess they could be doing that at the driver/API level, but then couldn't Sony just implement an API for backwards compatability mode that does the same? Anyway I am just thinking out loud. I hope you stick arround, it would be good to have someone who actually knows about this stuff arround. |
Direct X 9 series of cards can't use stuff from Direct X 10/11. Shader programs written in Direct X 10 fully won't work in 9 (Unless you wrote them in 9 in the first place like Crysis). And you're right, the unified shader architecture vs dedicated pipeline was the real problem with the PS3. Hell the PS3 at launch was actually closer to a PC than the 360 was, but between the pipeline issue, OS footprint, dedicated ram vs unified, those were the real issues. A good example of unified shaders vs dedicated would be Tomb Raider Legends. The "next gen" features in the game would bring the game to a crawl no matter what video card was used. Even the Geforce 9 series of cards had problems. And why? Cause Crystal Dynamics just threw the 360 game on a DVD and hope it worked, which is what was happening with early PS3 games.








