PS3 vs XBOX360 (long post)

[JPFS1]

well it seems XBOX360 is still in the running when it comes to pure grunt when compared to the PS3.

Initially, after only reading the specs and not looking much further into it, it looked like the PS3 had it all over the XBOX360, seems that is not the case.

For those interested, i've researched both consoles closely, looked at many official releases and technical specs and have come up with the following.

It seems the XBOX360 will actually be the one with more grunt based on some simple tech numbers and not so simple tech numbers.

based on specs provided by both manufacturers, the XBOX360 will;

1. have better main CPU performance based on it's more efficient and usable design
2. have a more powerful GPU
3. have a far greater memory bandwidth

now the reason the XBOX360 should have better CPU performance over the PS3 is that they have designed ALL 3 cores to include cache, branch prediction and a vector unit, this is extremely important because it is said that games are primarily designed to used these functions, roughly about 80% of the time, the PS3's SPE's (7 of them), don't have cache, direct access to random memory and no brach prediction. What the SPE's are great at is streaming floating point calculations (SFPC) where it is roughly twice as powerful as XBOX360, but in reality, SFPC is a much smaller part of a games code, actually the numbers for the next gen games are somewhere between 10%-30% for floating point, and 5%-10% for streaming floating point.

The PS3' main CPU also has a different instruction set to the SPE's, so this i would think would make it more difficult for programmers as they would need to write unique code for the SPE's.

The GPU of the PS3 is said to be about 2 times faster than the 6800 ultra of which it is based on, graphic numbers that i've seen for both seem to be very close, but the XBOX360 gets its nose infont... however, there are some technical design unknowns of sony's GPU as in how close it is related to the 6800 ultra's architecture, there may be some differences that will contribute to better performance, but it's close.

Memory bandwidth, this is a BIG difference, the PS3 has 22.4 GB/s of GDDR3 bandwidth and 25.6 GB/s of RDRAM bandwidth for a total system bandwidth of 48 GB/s, this may prove to be very limiting for the next generation requirements, they are using however Z buffer and colour compression technologies to compensate this limitation, these are said to break down though when rendering complex high quality 3D scenes.

The Xbox 360 has 22.4 GB/s of GDDR3 bandwidth and a 256 GB/s of EDRAM bandwidth for a total of 278.4 GB/s total system bandwidth.

There has also been some controversy surrounding some PS3 games shown at E3, where they say that CG was used in place of in game footage, ala Kill Zone, but there have also been some really really impressive ingame footage shown, ala I-8.

Saying this, the PS3 will still be a ripper of a console, much much faster than the previous console, just might be a bit more of a pain to code for and may have some shortfalls, the developers may even have some tricks up their sleeve, while the XBOX360 will be a lot closer than first thought.