RAM Help

[Millss1985]

Heyo, been having some issues with my computer constantly BSODing on me. Research and such has lead me to believe it may be RAM related with ntoskrnl.exe being the common denominator in the majority of my of my BSODs. I started to remove my ram 1 by 1 to see if my system would continue to crash in hopes to isolate out the bad RAM if thats the issue...but i ended up coming across another curious thing that i cant seem to figure out.

I have an ASUS M4A785TD-V EVO motherboard with 4 DIMM slots for RAM 2 side by side blue ones DIMM_A1 and DIMM_B1 and DIMM_A2 and DIMM_B2 in black. Ive noticed no matter how i line up my RAM i dont seem to get the correct amount of GB as the total of my RAM. I Have:

2 X G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
2 X G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)

With all 4 in it seems to only add up to 12GB on Windows 64-bit Home premium which ive read should have a max of 16. If i try the 2 8GB's it only amounts to 8Gb and a single 8 amounts to 4GB. I've tried to read up on this best i could but its not sinking in and still not fully understanding what im missing, or whats set up incorrectly.

Any help would be appreciated.

[Calum]

First thing I would do is try each stick of RAM individually in each slot.  You most likely have a bad slot on the board which is either not detecting the RAM or is not accessing it correctly causing your crashes.  The other possibility is that the IMC on your CPU is going bad or otherwise not doing what it should - you could try reseating the CPU and double-checking that all the pins are straight, just to rule that out.