Basically, I've had this q9300 @ 2,5 GHz for 2 years, and recently tried messing around in the BIOS. My memory is 2 GB Kingston PC2-5300 on a P5K premium board.
Since my FSB is currently at 333 (x7.5), and my RAM frequency is also at 333, does that mean I can't increase my FSB to 400? What would happen if I increase my FSB to 400, and set RAM frequency from auto to 800 MHz? My DRAM timings are 5-5-5-15
First, if CPU-Z is displaying an FSB:RAM ratio of 1:1, your RAM settings are all right. CPU-Z makes a distinction between RAM frequency, which in a Core2 system matches the FSB freq, and RAM clock, which is twice the FSB freq (DDR2 transfers two chunks of data during each bus cycle.
You should be able to push the RAM a little higher. Take your RAM settings off Auto and at stock FSB freq, set the memory clock to 667 MHz. Increase the RAM voltage to 2.2 volts if it already isn't. Then relax the timings to 6-6-6-18.
Now you can do the usual overclock stuff - increase bus speed, test, increase CPU voltage, repeat.