finally have some time get my hands on Xeon system.
spent lots of time on pin VID mod and achieve these results.
will try vmod for SM X7DA8 and bench under cold later.

Intel Dual Xeon 5350es B3 (BSEL Mod to 1333fsb / VID Mod to 1.5v)
Supermicro X7DA8 on stock with 5*strong fans all over the mobo (Strong Mobo)
Supertalent FB-Dimm 667 1G*2 on stock. (Really really good ram for Xeon OC)
Koolance Watercooling System (2*CPU-330, 1*RP-1000BK, 1*EHX1050w)
Topower 1200w PSU
8800ultra

vcore idle= 1.45/1.46v
vcore load= 1.38/1.4v
ambient=21c


stability test: 3.55Ghz 8*Prime95 15min


410fsb=410mhz memclk 3Dmark06 benchable, really amazing Supertalent FB-Dimm and Supermicro mobo.
And...it's not the limit


3.67Ghz 3Dmark06 Cputest, fsb=ram=408mhz, CPU score=7921


3.7Ghz wprime1024m, break 3min barrier


3.74G wprime32m=5.766sec


time to push more.
8cores at 420fsb, really need vMCH/vTT mod now


Suicide Screen at 3855mhz 8cores.


and...4039mhz single chip, 4cores


too tied now, gonna have some rest and will go on