GZ: "Ever wondered how fast each console’s operating systems run? Wonder no more. Legendary NeoGAF forum poster TTP has been busy compiling information on the speed that both the PS3 and Xbox 360 perform certain tasks. The results were generally similar for each of the operating systems, but there were some surprising differences."
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Trophies/achievements 7 times faster on 360
Official MMORPG Blog of MMOGA