Before doing anything today, I switched the speed of all the case fans from low to medium. This resulted in about 2C drop in both the motherboard and CPU temperatures.
My objective today is to get CPU and memory frequencies and voltages from their auto settings to manual.
The first BIOS change I made was to set the CPU VCore Voltage to 1.4000V (CPU frequency was already set to 266MHz), restarted and checked to verify that everything else was working properly. I left Nighthawk running at this setting all morning while closely monitoring temperature and voltages - no significant changes.
When I was convinced that I still had a stable system, I shut down and made the following changes to the memory settings:
DRAM Frequency: DDR2-533MHz
Memory Voltage: 2.25V
Configure DRAM Tuning by SPD: Disabled
DRAM CAS# Latency: 5
DRAM RAS# To CAS# Delay: 5
DRAM RAS# Precharge: 5
DRAM RAS# Activate to Precharge: 15
DRAM Write Recovery Time: 5
Static Read Control: Disable
I also disabled ASUS C.G.I. at this time.
I saved & exited BIOS.
Note: It is normal for the system to power off momentarily and restart after making these types of changes.
Nighthawk restarted normally and I quickly verified that the DRAM:FSB Ratio was set to 1:1 (it was originally at 12:8.) I ran 3DMark06 to see what the impact of this ratio change was. The system actually scored 8544 3DMarks at this 1:1 ratio which is higher than the prior 8529 3DMarks at 12:8 ratio. You can draw your own conclusions from this result.
Nighthawk is currently running at around 50% CPU Usage with the Motherboard temperature at 30C/86F and the CPU temperature at 49C/120F, with the CPU fan running at around 1767 RPM. The BFG Nvidia 8800GTS GPU temperature is at 55C/133F, for comparison.
All the preparatory work is now completed. I will leave Nighthawk running Memtest86 all night and if there are no errors detected, I will make the initial overclocking change to run the CPU at 300MHz (3GHz at the default 10x multiplier) and memory at DDR2-600.
It will be interesting to see how this initial overclock will affect the 3DMark06 benchmark. I am specially interested to find out whether the Nvidia 8800GTS has been constrained by the Core 2 Duo E6700 processor running at its default clock speed.
We shall see tomorrow.