That Guy on 26 March 2007
Wii has ~729mhz IBM Power 3 RISC CPU, x-box is ~733 Mhz intel pentium 3 CPU so cycle for cycle the Wii is twice the speed of the x-boxl.
Lemme put my two cents into it too. Yeah, as a general rule of thumb, you have to multiply RISC (IBM's Reduced Instruction Set Computing) by about 2 (though i've heard numbers as high as 2.5) to get a comparable CISC (Intel's Complex Instruction Set Computing) performance level.
Imagine that you're moving and you have to haul 1000 pounds of bricks and take it from San Francisco to Los Angeles. I have a Ferrari (a Pentium) that can haul 500 lbs at a time, but can go 100 mph. At the same time, i also have a Ford Truck (a PowerPC) that can haul all 1000 lbs of it at a time, but can only go 50 mph. Ignoring the fact that the Ferrari would have to make a return trip in order to pick up another load of bricks (which would effectively destroy my analogy), the Ford Truck, even though much slower than the Ferrari, can do twice as much work per trip.
To make things even Murkier, you have to also take things into consideration like Bus Speeds, RAM speeds, Hard Drive Speed, Cache, etc. etc. so its almost impossible to make a definite comparison between Pentium and RISC
So I think the 360 has something like a 3.1 Ghz PowerPC chip in there (or three? I forget), which pretty much blows away whatever the Wii has.
By the way, I've always argued that the GC was just as powerful as the Xbox, on account of this RISC vs. Pentium comparison. Didn't the GC have a 400 Mhz PowerPC chip as opposed to Xbox's 733 Mhz Pentium?
::EDIT::
and also everyone appreciates good graphics, but I know my fair share of people who still play old SNES RPGs on err....... legal backups of games they originally own.....
And also things like XBLA and Virtual Console wouldn't exist if graphics were the only thing that mattered