So i bought a new Intel E5700 dual core (45nm) 2MB cache processor. I was running it at max multiplier 15X till now and reaching 3.0GHz speed.

Now i wanted to raise the FSB speed a little over the stock value of 200MHz. So logged into bios and started increasing the FSB speed slowly to 266 MHz to make the effective FSB to 1066 MHz. Before starting with this, i cross checked my DDR2-800 RAM specs, the DRAM frequency was 400MHz and DRAM:FSB ratio was 2:1.

There was one big problem, as soon as i started increasing the stock FSB speed, in BIOS, the RAM frequency setting choices were also increasing and they read "DDR2 1066 .....". So i chose it AUTO, but after saving and restarting, the message came that there were repeated boot failures.

I changed back to old FSB of 200 Mhz and loaded windows (XP), and i tried the ASROCK OC tuner, even in that, after i clocked slowly to >230Mhz, the system hanged.

Am i doing anything wrong, or are my calculations of DDR2 speeds wrong? As i checked the DRAM:FSB ratio as 2:1, that means that RAM was running at 400Mhz on a 200Mhz FSB. So theoretically, the same RAM speed should work on an FSB of 400 Mhz with ratio of 1:1, isn't it?

Then why is the RAM frequency options (they won't show DDR2 800 anymore) change by themselves after i increase the FSB frequency in BIOS? Help will be much appreciated guys...