1066mhz lang sa bios nalilito ako sa xmp. chaka sa windows 3gb lang.

You have to manually set it to run at your desired speed, but remember that once you go over a certain speed you need more QPI/VTT voltage. If you want to run the Ram at DDR3-2000, you'll need more QPI Voltage. Which I never tried, cause I'm just after everyday i7 920 at 3.6Ghz, Mems (QPI voltage) at minimal OC.
Leave your CPU Clock Ratio to [21]
BCLK [Enabled or Disabled]
BCLK Frequency [133]
X.M.P [Disabled]
System Memory Multiplier [set it at x8]
I suggest, set your RAM timings to 9-9-9-20, vDIMM to 1.65v.
In the Memory Frequency, say you have 1600, then your Uncore Frequency should be around 3200Mhz or 3400Mhz.
3.50GB of Ram...bro you must be still using 32bit Windows XP. You need 64bit OS to detect Ram above 4GB.