brendude13 said:
Badassbab said:
It'll put it another way.
360 has an Edram memory set up. So you have VRAM, RAM (Both share 512MB) and embedded EDRAM (which is 10MB). The framebuffer (i.e the resolution and AA amongst other things) needs to fit within the Edram (which is 10mb in size). If it doesn't fit in then the programmer either has to downgrade something like for example the resolution until it's small enough to fit or resort to predicted tiling which can in some cases lead to performance issues as it uses CPU resources. However if the framebuffer does fit, then the 360 get's tremendous amounts of bandwidth (278.4GBs vs 48GB for PS3). This is why more 360 games feature higher res transparency effects, computationally expensive shadows, depth of field, motion blur etc.
PS3 has a traditional split memory architecture. 256MB VRAM and 256MB RAM. The frame buffer uses up the VRAM on the PS3. So basically that's 256Mb for the PS3 vs 10Mb for the 360. Because of this the PS3 can be triple buffered. Framebuffers not an issue on PS3. The issue with the PS3 is it's weak GPU but it's ok now because programmers can offload tasked that were meant for the GPU onto the Cell's extremely fast SPU's. Put it this way the 360 has 3 x 3.2Ghz processor cores, PS3 has 1 x 3.2Ghz main processor core but 8 SPU @ 3.2Ghz each, 6 of which can be used for gaming (one is disabled and the other is used for the OS). So basically the PS3 can be 720p with all the bells and whistles due to the traditional memory set up and the Cell processor. 360 could've as well if MS hadn't been so short sighted with only 10Mbs. It really needed to be 30Mb to compete against the likes of Killzone 3.
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Ahh ok, I get you now.
Just one question:
Why can't everything that is supposed to fit on the EDRAM be put onto the VRAM (shared), like the PS3?
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Because the 360 has a dedicated Edram frame buffer set up hardware. It can't use the Vram, it has to use the Edram or tiling for all render targets. While the Edram was a brilliant move the size of it wasn't. If the Edram was say 30MB then it's likely all 360 games would be default 720p with 4xMSAA (the max the 360 GPU allows) all the good bit's like DOF, SSAO etc. I don't think MS foresaw this gen lasting longer then normal. Sony on the other hand did though it too made some bad hardware decisions.
