I know this topic has been covered 1000 times probably, but I still CAN NOT find a solution for my problem.
The problem: When I boot my computer, it's showing my ram speed as 667 MHz, 4-4-4-12 with 2T timing, Dual Channel Enabled. However, in CPU-Z and SiSoft Sandra, it it showing up as 168.7MHz. When I set the frequency to 533MHz, it shows the frequency as 133MHz in CPU-Z and SiSoft Sandra.
System Info: Corsair XMS2 TWIN2X Matched Pairs 2x512MB DDR2.
I have the latest (0501) Bios for my Asus P5ND2-SLI motherboard. In the BIOS, I have disabled SpeedStep and Enhanced C1. I disabled all those N.O.S. overclocking options and set overclocking to MANUAL. I set my timings manually, 4-4-4-12-16-2T. My DRAM voltage is set manually to 1.9V. My FSB is set manually to 800MHz QDR. My DDR Frequency is set manually to 667MHz. This is a fresh system, I just bought it Sunday.
I don't understand why this is happening. I also noticed that if I set 1T instead of 2T, I get WORSE frame rates in Half Life 2. So I use 2T.
FSB is "quad-pumped." Calling it a 533 MHz, 666 MHz, 800MHz, whatever, bus is a misnomer. Data is transfered 4 times per clock, so Intel likes to use this to call a 133 MHz bus 533 MHz, a 166 MHz one 666 MHz, etc etc.
In short, CPU-Z is right and there is no problem. That is the real clockrate at which your RAM is running.