I've just got a new P5W DH.
Its lot is 6CM, so manufactured in Dec. 2006, I think.


The board revision is 1.04G...
...Vmch=1.85V setting is available, of course.


Then I tried FSB overclockability test with Kentsfield QX6700.
The test is very simple...finding max FSB for ORTHOS 3min running.
Test condition: Vmch~1.85V and MCH water cooled for each case.

Results:

P5W DH(lot:67M) ~ 342MHz
http://www.oohashi.jp/c-board/file/O..._342.5_3-4.png

D975XBX2(REV.502) ~ 384MHz
http://www.oohashi.jp/c-board/file/O...XBX2_383.9.png

P5W DH(lot:6CM) ~ 398MHz


The lot of MCH chip is:
My old P5W DH (lot:67M) -> L552A722
My D975XBX2 (REV.502) -> 3625B181
My new P5W DH(lot:6CM) -> 3644B182

So, newer MCH brings more overclockablity for Kentsfield, it seems.
Yes I know that P5B series(P965) are more Kentsfield friendly,
but 975X is still slightly faster than P965 at same clock...
...P5W DH is not dead, especially for multiplier unlocked Kentsfield