Modifying A 133 Fsb T-bred B Into 166 Fsb
We mentioned earlier that there differences between Barton and TBred-B in terms of their L12 bridges. The difference can also be seen with the Athlon XP 2700+ and 2800+, which share a 166MHz FSB. Would it be possible to go straight to a 166MHz FSB by changing the L12 bridges? We decided to test this with a TBred-B Athlon XP 2200+....

To reconnect the two severed L12 bridges, we will use the same method used to unlock the multiplier. Apply correction fluid to the gap in the second bridge from the right (the bridge we will attempt to connect), then tape the adjacent bridges to prevent short-circuiting. Then connect the bridges using a conductive silver pen. PC booted and the BIOS quite clearly shows a 166MHz FSB. A simple L12 connection to unlock 166MHz FSB speeds seems to be well worth the effort – if you choose to unlock the multiplier, unlock this higher FSB setting as well to give a significant performance boost.

Modifying A 133 Fsb T-bred B Into 166 Fsb

Possible Solution for Running High FSB
On my 2700 and other new chips, they ran cut-connected-connected-connected. These bridges set the default FSB, with the former being 133, and the latter being 166. To test whether this affected the chip being able to run a high FSB in this board, I connected the third L12 bridge (one away from the "L12") on Aceman's 2200 - This would in effect make it look like a new XP2800 (166x13.5). We began testing and the chip was defaulting to a 166 FSB.

Possible Solution for Running High FSB

Source | neowin