How much faster is Windows 7 compared to Ubuntu 10.10

[artantaaa]

I'm currently running Dolphin in Ubuntu 10.10 on a core2duo E8400 3.0 GHz/ Nvidia 8400. It runs Gamecube and some of the less demanding Wii games at full speed, but many are slow. I was wondering how much of an improvement I would see if I were to run Windows 7 on a spare drive I have. Would there be a significant difference? If I would only gain a few fps, it wouldn't be worth the trouble to me, so I'd like to hear the opinions of those who have used both.