Well I upgraded from a xp-m 2400 @ 2600mhz, to my current 146 cabye 540.
And straight out of the box had it running @ 2800mhz, its loads faster.
Last night I had it running at 3100mhz on 1:1 with my Geil one memory, stupidly fast in Doom 3 ! no volt mods still using 1.45 on my asrock sata2
Then I got bored and tried for 3200mhz still using my artic cooler 64 pro, It didn't work ! probably need more volts.
As I seam to remember even the worst Opteron 146's where something like "CABYG" stepping and they Oc'd to 2700 and everyone complained that they where naff !