Bios and Win7 64bit not recognizing all RAM

[colvert]

I have an Asus p7p55d motherboard with 4gb of DDR3 1600 ram (12800CL9D-4GBNQ). I recently noticed a slight drop in performance and while investigating the cause I found that Windows 7 sees 4gb of Ram but it says only 1.99g usable. I have unchecked the max memory setting in msconfig to no avail. Also, under the system information in the Bios, it says only 2096 mb of memory is available. My bios does not recognize all 4gigs. The memory remap setting is enabled in bios too. I ran memtest and no errors are found. And CPU-Z also shows 4gigs of memory. Why does my computer not utilize all 4 gigs??

Specs:
- Intel Core i5-750 Lynnfield 2.66GHz LGA 1156 95W Quad-Core Processor Model BX80605I5750
- G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Dual Channel Kit Desktop Memory Model F3-12800CL9D-4GBNQ
- ASUS P7P55D LGA 1156 Intel P55 ATX Intel Motherboard
- EVGA 512-P3-N871-AR GeForce 9800 GTX+ 512MB 256-bit DDR3 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
- 550 watt power supply
- 320g HDD

[GSKILL TECH]

Reseat the memory and make sure it is firmly inserted. Then reseat the CPU and double check the CPU pins on the motherboard. If you continue to have a problem, simply send them in for new replacements.

Thank you
GSKILL TECH

[bummpr]

He's Right

GSkill Tech is right on...I had the exact same problem with this board and memory sticks. I'm not convinced that the ASUS slots with only one side that locks is a very good solution...memory sticks are fairly easily knocked ajar from full contact and this produces unusual side affects. I bet that CPU-Z shows you only have single channel memory installed.

As suggested, reseat all memory sticks and press them firmly on both ends. Good luck.

[colvert]

This is probably a completely simple question, but this is my first build... Is it necessary to reapply thermal compound to the cpu and fan? I took the fan off the cpu but did not have any stuff to put back on when i reinstalled it...

[Grimmett]

You really should remove the existing compound, clean off the heatsink and processor, then reapply thermal paste every time you remove the heatsink. If you didn't do that, be careful and monitor your temperatures really closely until you get some thermal paste.

Good Luck

[GSKILL TECH]

colvert,

It should be alright to simply reinstall. As Grimmett stated, you should watch your temps, but I'm sure you probably won't be maxing out and over-stressing your CPU any time, so heat should not be a factor.

bummpr is right, on ASUS P55 motherboards, the one side without a slot clip can easily be slightly raised thus not fully in contact with the memory slot.

Thank you
GSKILL TECH