yup benchmarks show this slows your machine down (and you can see why) the say your os is at the start of partition 1, if things are paged, they'll be on the 2nd partition (if you've set it up like that), so the disk will be going back and forth to the start of the drive to the start of your 2nd partition me too, some of the larger folders in programfiles can be compressed to save a lot of space as long as your core files and ones you use everyday (like ff) aren't compressed, you're not going to notice the difference in speed