By eva2000 
try raising North Bridge Voltage to 1.55v to 1.65v and DRAM voltage to 2.2-2.30v the higher voltages particularly for 4x1GB.. you can probably drop FSB termination voltage to 1.3-1.35v
24/7 i'd recommend NB 1.55-1.6v and vdimm under 2.25v vdimm
I ran Orthos CPU & RAM priority 10 this night by following your advice and Orthos crashed after 9 h 13 min.
Here are the parameters :
CPU Voltage: 1.5 V
CPU Voltage Reference: AUTO
Loadline Calibratiom: Enabled
FSB Termination Voltage: 1.38
North Bridge Voltage: 1.55
North Bridge Reference: AUTO
DRAM Voltage: 2.2 v
-DDRII Channel A Ref Voltage: AUTO
-DDRII Channel B Ref Voltage: AUTO
-DDRII Controller Ref Voltage: AUTO
South Bridge Voltage: AUTO
PLL Voltage: 1.54 V
I will test tonight with VFSB=1.34 V and VPLL=1.5 V. Indeed, accordinf to your link,
E6850 L723A347 + Asus Blitz Formula 1101 bios, you adjusted VPLL at 1.5 V. Today, I will play games too in order to see if I still encounter crashes.
I keep you informed.