If you're serious about gaming, you've probably already considered installing a special Linux box to achieve that famed 500 hz USB connection, for ultra smooth mousing.
If you haven't, here's the deal. Windows limits USB reading to 8 ms polls - 125 times a second - thus 125 hz. This is where the whole P/S2 vs USB thing started: P/S2 is tweakable to 200 hz polling, thus being almost twice as responsive as USB.
Until now, only Linux users (and then the users that were capable of recompiling their own kernels) were able to change the polling rate for USB.
Now, some nut cracked the WinXP limit, and Razer seems to be working on 'fixes' for other Windows versions.
Check it out here:
http://www.warleagues.com/viewnews.asp?view=45Since I'm still using Windows 2000 I can't use it yet, but damn this is sweet. Plus it finally should put a stop to the aforementioned P/S2vsUSB debate.
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If you don't know what I'm talking about, don't care or think 'you cannot sense the difference' - forget it. Just keep yer trap shut and sit back down :]