Tried this new memset with my DS3R, looks like the fastest performance on my board is 7 (around FSB 460-500MHz), default was 11. I also got my system locked up when I tried to change performance level to 6.

Also I noticed that my superpi is faster when I run my system at 460MHz (E6300, 460x7) dan change the performance level to 7, than boot from 416MHz and clockgen to 460MHz, and didn't change the performance level (at level 11). Screen shot @ pi 2M (quick test)

Boot from 416, clockgen to 460 = 41.875s


Boot from 460, set performance level to 7 = 40.013s


Also tested with Everest Cache & Memory benchmark, and also I got better result with performance level 7 (boot from 460), than boot from 416 (and didn't change performance level).