The 1066 FSB Woodcrests look to be the best current choice for overclocking. The jump from 1066 to 1333 FSB would net a modest 1.25x increase in clock speed. For this BSEL mod all that is needed is some insulation on the G30 BSEL2 pin! These xeons might do it:
Woodcrest 5110: 1.6/1066 to 2.0/1333
Woodcrest 5120: 1.86/1066 to 2.33/1333
Dempsey 5060/5063: 3.2/1066 to 4.0/1333
For the low-end Dempsey, going from 667 to 1066 is a pretty big leap with a 1.6x increase in clock speed. Not as likely to happen. The slowest Dempsey at a natural 2.67GHz would have to do 4.3GHz at 1333. If the motherboard allows lowering the multiplier it could work. Or if there were an undocumented BSEL for 800 FSB, and the motherboard supports it, it could be useful when the prices drop to near-free like the early P4 Fosters and P2 Xeons are today.
The high-end Woodcrests with a 1333 FSB will have no current overclocking path since they already have the maximum known FSB. Lets cross our fingers that Intel in the near future will make use of some of the many reserved BSELs, preferably something a little higher than 1333, and that current boards will support it.. If they are in the 101, 110, or 111 BSEL's it would be an easy insulation mod from 1333 FSB BSEL of 100.
