CPU & RAM

Use the BIOS

System specs? What kind of motherboard?

To run 1:1, your memory clock frequency has to be twice the FSB frequency.

I am assuming you are running a Core2 CPU. Somewhere in the BIOS (that's one reason we need specs), there should be a setting for the memory clock multiplier. Different motherboards and BIOs's call it different things. Take it off [AUTO] and set to the first 2.00 setting you come to.

it can be any ratio u want. the "1:1 a must" ratio is a myth. actually, the higher u can raise your ram fsb, the better ( with decent latencies, of course).
your system might restart several times till the board set the correct ram timings. try manually setting the RAM latencies, see if that works.

Actually, that is not exactly true. There's no question that running the RAM at less than the CPU will have a deleterious effect on system performance. Running the RAM faster has a small positive effect on memory benchmarks at the cost of an increase in instability, but no gains in real world performance. You will gain more by running the RAM at 1:1 and tightening the memory timing. It depends on whether you are building a machine to run benchmarks or to actually do something.

After the 4-4-4-12 or "whatever you need to make it run" settings, I think you reach the point of diminishing returns. I leave all that stuff on AUTO or let the BIOS select what it thinks it needs. I've been doing this a while and there just comes a point where if you need a really good memory benchmark to tell the difference, you have reached a good place to stop.
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Building computers since 1977.
Overclocking since 1978 - Z80 (TRS-80) from 1.77 MHz to 2.01 MHz

so what u are saying is that, 4-4-4-12 @ 800 Mhz is better than 5-5-5-15 @ 1066 Mhz ? I personally believe that the difference is so small that only a benchmark can notice, there wont be real world benefit. At least not as much to put that "1:1" ratio in every newcomer's head.