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[68HC000]

I've been reading up on what some developers have been saying about the performance of the Xbox 360s CPU and its surprising... but then again its not when I think about it. Developers are saying its CPU is a little more than 2x faster than the 733 MHz Xbox CPU (in performance not numbers). It makes me wonder if Micro$oft over extended the pipeline of the CPU to allow for inefficient 3.2 GHz operation in order to say "Hey! 3.2 GHz BABY!!!".

 Something else to consider: IBM does not make a powerPC 95xx (G5) CPU that is even close to 3.2 GHz. I think the graphics subsystem in the 360 is superb, but the CPU just doesn't impress me.

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This post has been edited by 68HC000: Aug 1 2006, 03:11 PM

[twistedsymphony]

This is news to me, do you have a link to these developer claims?

[68HC000]

Of course no one developer is going to put their nuts on the chopping block releasing a statement, but if you google "Xbox 360 cpu performance" there are several articles listed (along with the facts I stated above) that have lead me to believe that its performance is not what the clock rate might have you think.

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[thax]

He is talking about the AnandTech article that came out about a year ago and was quickly retracted. I wish search worked because that discussion article would fully explain the misconceptions about the performance.

The second point being the multi-threaded processing, where as single threaded games only run about twice as fast. This was a known problem by MS, this is somewhat mitigated by only having 3 cores vs. 7 SPE's like the PS3.

The third point is that the CPU doesn't deal with out of order execution and branch prediction as easily as say a P4. This means unoptimized code runs slower. Once code is properly written for the PPC then higher performance than an P4 with an equivelent transistor count can be obtained.

All of this is difficult and challenging work, but allows for a higher level of theoretical performance. The PS3 requires even more work, but once again there is a higher theoretical peak performance. You can look at the PS2 CPU in the same manner, it is simply mind boggling what developers are able to produce with such limited resources. Where if you look at the xbox, there isn't much room for optimization to get an extra level of performance out of the console.

The x360 CPU is capable of some amazing performance, and the same goes for the PS3 CPU.