ASRock P43Twins1600 Ram Problem

[1stgen7]

Just got my newly built computer up and running.
ASRock P43Twins1600 mobo
Intel E7200 2.53ghz (overclocked to 3.0)
XFX 9800 GTX+
OCZ Fatal1ty 2x2gb ddr2 1066 PC2(8500)

Everything seems to be working well, but I am having serious problems with the memory. First it only runs at ddr2 800. When I try to turn it up to 1066 manually in the bios it refuses to boot. I can deal with it running a little slower, but what I don't like is that it only registers as 3.18gb of ram in XP (and on boot screen). In the bios, it recognizes the full 4gb, but I can't seem to get it to work correctly past that. The timings seem correct, but I don't know all that much about timings. If anyone could help me I would greatly appreciate it. (First time computer builder)
Thanks,
John

 

[o1die]

As I pointed out in another forum, when you overclock the cpu, the memory is also overclocked. So the board bios may have a built in memory divider that reduces the memory speed automatically so the cpu can be overclocked. If you're overclocking the cpu by 25%, then the memory may have to be run 25% slower. The 2 are tied together. Also check your board default memory voltage; you can reduce windows bluescreens by increasing the memory voltage manually in the bios to 1.9-2.1. All ddr2 memory rated higher than 800 fsb will normally run at a higher voltage than 1.8, which is the normal standard for pc6400.

 

[ldog]

2 things I'd recommend:

1) Check your FSB jumpers (pg 23-24 in the manual ) to get your CPU freq to match (like the previous poster mentioned)

2) Enable your "Memory Remap Function" in the BIOS Advanced/Chipset Configuration section. This let my 64bit Vista see all 4G of RAM.

HTH