Full 4GB Capacity Not Registering

RamGuy:

Some background:

I recently RMA'd some RAM that went bad on me (TWINX2048-3200) and was sent back a different pair (TWINX2048-3200C2PT). This new RAM has different voltage and latency than the original pair. I needed to keep my machine running while the original 2GB sticks were in transit, so I purchased some less costly and readily available RAM (******** PSD2G400KH). This ram matched the Corsair pair specifications (voltage, CAS, etc.). I just assumed when I received the RAM from Corsair, I would have four 1GB sticks maxxing out my mobo at 4GB.

The problem:

When I received the new pair I installed them in the "blue" position (A1, B1) and the other pair in the "black" position (A2, B2). The system seems to be very laggy, graphics and games are choppy, and the system only posts 2.5GB as a RAM capacity.

Any suggestions?

If you are running with a 32bit OS then you will not see the full amount of the DRAM. Only 64bit OS's will show the full amount and only if the motherboard allows for a remapping of the memory and I'm not even sure if your board allows for that.

http://www.houseofhelp.com/v3/showthread.php?t=49816

When you populate with four DRAM slots you are advised to drop the bandwidth. Set your DRAM frequency from DDR400 to DDR333.

Please research this thread regarding running with a four DRAM slot population. This issue is well documented. When you populate all four DRAM slots it is advised to drop the DRAM bandwidth. Please take your time to study this thread.

http://www.houseofhelp.com/v3/showthread.php?t=64360&highlight=Unpredictable+results+QUAD2X4096+Gigabyte+X38-DS5

Post any questions you have that this thread does not address. You can also check with any other forums for additional information if you wish more information or more opinions.

Some of the forums you can check are:

http://forums.anandtech.com/messageview.aspx?catid=83&threadid=2188593&enterthread=y

http://forums.cnet.com/5208-7591_102-0.html?forumID=26&threadID=294863&messageID=2773366

As well, just look on this site or any other DRAM memory site and you will see many, many posts of people attempting to make their systems stable with all four DRAM slots filled. Check other manufacturers help forums to see that this issue is regardless of manufacture of the DRAM since the issue is the memory controller.

http://www.houseofhelp.com/v3/showthread.php?p=351707

http://www.houseofhelp.com/v3/showthread.php?t=64360

http://www.houseofhelp.com/v3/showthread.php?t=69449

http://www.houseofhelp.com/v3/showthread.php?p=351034

With that board, I believe you would do better with population of two DRAM slots rather than four.

Load setup defaults. Save setup defaults. Set the DRAM to 333Mhz. Disable USB Legacy Mode. Test with memtest86+ V2.01

and extract the ISO image. Burn the ISO image to an CD-ROM disk.

Run Memtest for two full passes, then (If Stable), enter Windows and post screenshots of CPU-z's CPU, Memory and SPD tabs.