It would be nice to know what CPU and mobo that you're running. I'm assuming at this point that the CPU has an unlocked multiplier. But yes, I've found that overclocking the CPU is more important than the ram speed.
Ok. Yes, overclocking the CPU will help, not only for the CPU, but for the ram speed itself as tey are linked. You will need to raise the voltage of the ram and the CPU. Can't say how much, as each component is an individual and what works for on CPU may not for another. A general guess would be someplace between 1.35v and 1.4v for the CPU (VCore). The ram voltage I used for DDR2-800 ram was 2.2v. Tom's has a general guide for overclocking:
I'm assuming right now that you are new to overclocking. Not to worry, everybody was at one time.
Raise the CPU (VCore) and ram voltage one step and raise the overclock one step. If you're having trouble because the computer is crashing, its most likely not got enough voltage to the VCore and/or ram. I don't know the voltages on your setup, so you'll need to refer to the manual. You can also try Gigabyte, Intel, and the company that made you ram for specifics. As you overclock, use Coretemp to monitor the CPU temperature. If you don't have an aftermarket heatsink, get one. I used a TRUE on my QX9650 for years and it always did a good job, but there are a few other tower type heatsinks that are good as well.
After you raise the clock a bit, run Prime95 to both verify that nothing is crashing and watch the temps at the same time. Most likely you won't get the ram up to exactly 800mhz, but you can get it close. Hope all this is a help for you.
My RAM is supposed to run at 800mhz but it wont it just keeps crashing.
Your ram timings may need to be manually input and/or relaxed. Usually ram will run fine at its rated speed and timings. You shouldn't push your ram voltage too much. Find out what your ram's rated voltage is. If your ram is rated at 800mhz then it shouldn't need more than its rated voltage.
I appreciate your responses Sailer and larkspur. All that info you provided is extremely helpful indeed.
Yah, I am new to overclocking, just fancied learning this weekend
Voltage to RAM is currently 2.1v which is stock default.
Ram runs fine at 638 mhz just doesnt load windows if raised to 800mhz, so I might try either relaxing timings or tightening them...
I was kinda concerned that the 'Rated FSB' is running at 1065mhz - I didn't want to blow it up or stress it too much. The actual fsb is 266 but I read that it's quad pumped, which is, (apparently), where the figure 1065 comes from...
Go through the guide. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier from AUTO to 2.00 to set the Memory Frequency to twice the FSB. Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB of 266 MHz, your memory clock should be at 533 MHz. That will seem low if you have DDR2-800 RAM. Don't worry about it.
Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio. Do not worry about trying to overclock the RAM. Performance gains will be minimal, if any. CPU speed and stability are more important than RAM speed.
Do not exceed 1.45 volts on the CPU cores and keep your load temps under 70 C.
The CoolerMaster Hiper 212+ ($30) is a very good cooler for the money. It should be all you need for a dual core CPU.
You should be able to reach 3.3 GHz or so at a minimum.
I like the G'byte Core2 boards. I have several:
GA-EP45-UD3P | Q9550 OC'd to 3.6 GHz (425 MHz X 8.5) C3 stepping
GA-EP45-UD3L | Q6600 OC'd to 3.6 GHz (400 MHz X 9)
GA-EP35-DS3P | E7500 OC'd to 4.1 GHz (373 MHz X 11)