PS3 Has “Tight memory, Poor IO Performance” – John Carmack

[Booh!]

Rainbird said:

Booh! said:

Rainbird said:

He was asked why the PS3 version didn't perform better than it does and he answered the question. It's got nothing to do with whining. Not to mention that the move to focus on consoles is userbase-related rather than technology related.

No. He was requested to let us know if he could improve the game performance on ps3 or not. He was clearly pissed off and gave this harsh answer, that sounds a lot like an excuse. Q. : "Be professional and speak clearly: can you do something better?" A.: "The hardware is shit, it's not my fault".

It's an excuse. He could have simply answered that he had not enough experience on that kind of hardware, that he had not enough time to optimize the performances, that he miscalculated the tasks for those hardware capabilities. But saying that is just an excuse, 8Gb is not the largest install, and RAM is not that tight (it's even on a double bus, a feature that common pcs have not)...

Pissed off? Harsh answer? The only thing he said that might sound like that is "poor".

"we don’t know of anything we can do to improve ps3 performance much, especially on wasteland. Tight memory, poor IO performance."

And even then, what he said is true. Sony only allows a 5 GB install normally, so RAGE is definitely an anomaly, and RAM is tight. There is only 512 MB in total, but the RAM is split, so you have to spend ressources transfering data between the two parts, not to mention the OS takes up space.

Compared to the 360, the 360 doesn't need to transfer data between two RAM parts, it has the 10 MB additional RAM for the currect frame, and the OS generally takes up less space than the XMB.

Not shared RAM (like on the ps3) is the best and more costly solution, especially if you have multiple busses (like on the ps3). I don't want to start a discussion about the strong points of such an architecture, since the problem is not there.

Megatexture is a very bad idea for a ps3 and that's a Carmack's fault. If you want to get the best performance out of your software, you have to adapt your software to the architecture, not the other way around. Instead firstly he conceived the megatexture thing (which is a good idea, theoretically) and then tried to implement it on different architectures, even where it could be (and it is) not the best solution.

As a side note: tiled textures =/= always the same texture; you can take a megatexture, split it in a myriad of files (GT5 style) and then seamlessly load those files (you can do it if your ram is fast enough and by coincidence the ps3's got fast ram).