My board doesn`t like higher NB/VFSB-Voltages, but it`s ok, because the low voltages are stable
First I had my 450x8 settings from my old SE with 1,29VNB and 1,38VFSB in bios and they didn`t run stable. After going down to 1,25VNB and 1,20VFSB, which is board minimum, the settings were stable.
Here they are again:
BIOS 903
Extreme Tweaker
Ai Overclock Tuner : Manual
OC From CPU Level Up : Auto
CPU Ratio Control : Manual
-Ratio CMOS Setting : Auto
FSB Frequency : 450
FSB Strap to North Bridge : 400
PCI-E Frequency: 100

DRAM Frequency: 1200
DRAM Command Rate : 2T
DRAM Timing Control: Manual
CAS# Latency : 5
RAS# to CAS# Delay : 5
RAS# Precharge : 5
RAS# ActivateTime : 5
RAS# to RAS# Delay : 15
Row Refresh Cycle Time : Auto
Write Recovery Time : Auto
Read to Precharge Time : Auto
(missing setting?: Auto)

Read to Write Delay (S/D) : Auto
Write to Read Delay (S) : Auto
Write to Read Delay (D) : Auto
Read to Read Delay (S) : Auto
Read to Read Delay (D) : Auto
Write to Write Delay (S) : Auto
Write to Write Delay (D) : Auto
DRAM Static Read Control: Enabled
Ai Clock Twister : Light
Transaction Booster : Enabled
-Boost Level 0

CPU Voltage : 1.33700 | 1.312VCPU-z
CPU PLL Voltage : Auto | 1,65V Bios
North Bridge Voltage : 1.25 | 1.26V Everest
DRAM Voltage : 2.16 | 2.19-2.21V Everest
FSB Termination Voltage : 1.20 | 1.22V Everest
South Bridge Voltage : 1.050 | 1.06V Everest
Loadline Calibration : Enabled
CPU GTL Reference : 0.63x
North Bridge GTL Reference : 0.67x
DDR2 Channel A REF Voltage : Auto
DDR2 Channel B REF Voltage : Auto
DDR2 Controller REF Voltage : DDR2-REFF
SB 1.5V Voltage : Auto

NB LED Selection : NB Volt
SB LED Selection : SB Volt
CPU LED Selection : CPU Volt
Voltiminder LED : Enabled

CPU Spread Spectrum : Disabled
PCIE Spread Spectrum : Disabled
The last days, I tried to get 500x7 stable, to get an impression of voltagerange from 450 to 500fsb. So I optimistically tried 500x7 with 1,25VNB and 1,20VFSB, too. Got an OCCT error(slider to ram, very large) after ~8h.
Then I tried voltages from old SE, 1,29VNB and 1,38VFSB in OCCT, same test but error again after only 2h (after increasing voltage from minimum to a bit higher from after 8h error to after 2h error???).
Tried 1,29VNB but 1,20VFSB and it works, over 11h same test without any error:

Will test slider at cpu and at middle next days and post final 500x7 settings then.
Has anybody else noticed instability because of higher voltage, instead of low voltage? And I am talking about 1,38VFSB, which isn`t much, but I believe my system only runs good at minimum VFSB!?