|The P965 northbridge chip used in the Commando was the hot ticket until the P35 came along, then the P45. The southbridge chips were improved as well. The G31 is based on the P35 but it's for the "value" segment & is always paired up with the older ICH7. The Commando has the ICH8R & your P35 board has the ICH9.|
Regardless, it appears that all three boards are capable of handling a CPU frequency of 400MHz (1600MHz FSB) & since you have DDR2-800 RAM, you *should* be able to get a major overclock out of any one of them. Remember that the highest clock speed shouldn't necessarily be the ultimate goal, the highest stable FSB with the CPU:DRAM ratio running at 1:1 should be the goal. And since you have RAM capable of at least 400MHz frequency, you should attempt to take full advantage of it. I can only guess that you're not setting up the BIOS correctly.
I can only suggest a few generic things to do, the rest is up to you. The settings have to be manually configured. Do NOT rely on any built-in overclock settings. Generally, if there's a choice between Auto or Manual, choose Manual, then adjust the settings yourself.
- lower the CPU multiplier to take the CPU temporarily out of the picture - 6.0x for example? (lower, if possible)
- raise the CPU frequency to 400MHz (1600MHz FSB)
- do what you gotta do to run the RAM at 400MHz frequency (800MHz DDR) to match the CPU frequency. This is done in different ways depending on the board. If could be an actual ratio setting, or you may have to underclock the RAM setting so that it jumps up to the desired setting based on the CPU frequency/FSB.
- always set the RAM voltage as per the RAM manufacturer's specs. Don't except the BIOS default. If the voltage is spec'd at 2.2v, make sure to set it at 2.2v.
- always disable ALL Spread Spectrum options
- always disable EIST (SpeedStep)
- always lock the PCIe at 100MHz
- always lock the PCI at 33MHz
If you can pull off the above, the CPU will run at 2.4GHz at 1600MHz FSB with the RAM running in step at 800MHz DDR.
Then to increase the CPU clock speed, all you have to do is increase the CPU multipler a little at a time & see what happens. If it becomes unstable, increase the CPU voltage a little & try again. You *may* also throw a little more voltage at the northbridge too. But NEVER increase voltages unless you're absolutely sure it's necessary.