When it comes to max resolutions you need to look at 4 things
Pixel Fill rate
Texel Fill rate (not always 1:1 with Pixel fill rate)
Memory Bandwidth (both speed and bus width, which is 128bit with RSX)
GPU power
with the RSX, the core problem is really with 3 of those. with 4GPixel/sec fillrate, 12Gtexel/sec texture fillrate and Memorybandwidth of 22GB/sec, there simply isn't enough there to run games at 1080p without making serious concessions with what you want todo.
Developers have the following options
- Drop from 60hz to 30 hz
- Drop game's HD resolution to 720p (1024x720) from 1080p (1920x1080)
- Both of above
To get the detail people want in today's games, most developers end up doing both.
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RSX is based on the 7800 Architecture with the Xbox's Gpu based on the X1950 Architecture (just with the pixel pipeline and vertex pipelines unified), they both belong to the same generation on PC. While the PC versions of these cards are more powerful then what ended up in these consoles, gaming at 1920x1080/1920x1200 was really the domain of SLI/Crossfire users on PC (using 2 cards together instead of 1) if you wanted the high detail + AA + performance. Games today on console are more detailed then when these gpus ruled the PC land so its _really_ not supprising that 1080p is Rarely used on PS3.
