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New RAM problems

2K views 17 replies 4 participants last post by  Tyree 
#1 ·
I decided to upgrade the ram in my old PC from 1GB to 2GB. The ram I had was Corsair XMS3200 400Mhz 1GB but I know how mismatched memory can cause problems so I bought a new set of (2) Corsair XMS3200 400Mhz 1GB (each). Yes, I know it's the same thing but I wanted to be sure nothing had changed since the original memory was years older and the version number was the only difference.

I removed the old DIMM and installed the new making sure I used the proper slots to maintain dual channel operation (Slots 2 & 4). Shortly after the Win XP loading screen starts there is a BSOD, the specific error is different almost every time but it is always related to memory.

I tried booting into the Ubunto partition and everything worked flawlessly. I then went ahead and ran Memtest86 for two full passes with 0 errors reported. Ok the hardware is fine and Ubunto is fine so the problem has to be in Windows XP and the RAM.

Next I tried running each DIMM solo in slot two (same location as the original) and both times Win XP loaded and ran flawlessly on the 1GB. Finally I placed the DIMMS in Single Channel Mode (slots 1 & 2) and on Boot the BIOS gives a message:
"The system is running in Single Channel Mode when you plug DIMM Module in DIMM 1. Please install 2 Ram Modules into DIMM 2&4 for Dual Channel Operation."

It then allows me to press F1 to continue. In this single channel mode Windows XP boots perfectly and allows access to the full 2GB of RAM. I could almost live with this if not for having to press F1 every time I boot or restart the system. I have even tried resetting the BIOS to defaults, and disabling the DIMM Interleave.

I happen to have another machine that also uses PC3200 400Mhz ram. It had (2x) 512k 400Mhz ram from Buffalo so I decided to try it.

The Buffalo ram works perfectly in dual channel (Slots 2&4). So then I tried adding in the Corsair ram into the remaining slots (1&3). Low and behold it all works but Windows only shows 2.75GB....I thought the limit was 3.75 for WinXP?!?!? Anyway, so I then try swapping the Corsair and Buffalo around so the Corsair was now in slots 2&4 and the Buffalo was in 1&3. It still works (2.75GB shown).

I did notice that while both the Corsair and the Buffalo ram are 400MHz the Corsair is listed as CL3 while the Buffalo is CL2.5. When I boot with just the Corsair installed I see "DDR 400 CL: 3 1T (timing)". Booting with both sets installed I see "DDR 333 CL: 2.5 2T (timing)". So combining the RAM is lowering the Frequency, the CAS Latency and changing the timing.

I just don't get why all memory configs seem to work with the system itself, and Linux based OS's but just WinXP chokes when using the Corsair only in Dual Channel mode. I can't help but think the problem lies in how XP is handling the CL and Timing settings.

The problem can't be bad Ram since memory tests, the system itself, and Linux based OS'es all recognize and use the memory perfectly (single or dual channel modes) and even XP can see and use it in single channel mode. The problem is that XP will not even finish loading in Dual Channel mode. Nothing in the system is overclocked or used out of spec.

System Specs:
Processor: AMD Athalon 64 3800+ 2.4GH
System Board: LanParty nF4 Ultra-D
Memory: Corsair XMS3200 400Mhz 1GB (x2)

I appreciate any help available.
The Mav
 
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#3 ·
Windows Xp will not us more than 3.75 of available RAM. Only Xp 64bit will use the whole 4GB or more. All though Microsoft claims Windows XP will support 4GB of RAM but some people have problems after 2GB.

Plus sometimes if you mix non ECC and unbuffered with ECC buffered RAM that will cause different results in Windows XP.

I would recommend sticking with 2GB or 3GB max with XP.

What is the total RAM you are trying to use with XP?
 
#13 ·
Maybe this will help demonstrate the issue. There are RAM 4 slots and 2 different memory types (2 each). Type 1 is Corsair XMS3200 400Mhz 1GB, Type 2 is Buffalo PC3200 400MHz 512 MB. The key differences between the Corsair and the Buffalo ram is that the Corsair is 1GB CL3 1T and the Buffalo is 512MB CL 2.5 2T. Here are the possible scenarios and the outcomes:

SCENARIO 1: This works perfectly on everything
1. Empty
2. Corsair (either stick)
3. Empty
4. Empty

SCENARIO 2: XP will NOT boot in this configuration but Ubuntu and Memtest86 show zero problems with this.
1. Empty
2. Corsair
3. Empty
4. Corsair

SCENARIO 2: XP WILL run fine in this configuration but I get the Not Dual Channel message from the BIOS when I boot (see OP for specific message).
1. Corsair
2. Corsair
3. Empty
4. Empty

SCENARIO 3: This works perfectly on everything
1. Empty
2. Buffalo
3. Empty
4. Buffalo

SCENARIO 4: This works perfectly on everything but XP only reports 2.75GB instead of 3GB.
1. Corsair
2. Buffalo
3. Corsair
4. Buffalo

SCENARIO 5: This works perfectly on everything but XP only reports 2.75GB instead of 3GB.
1. Buffalo
2. Corsair
3. Buffalo
4. Corsair
 
#15 ·
#16 ·
Oh in addition to looking for "ganged or unganged" I also looked to see if there was anything with 128bit and 64 bit options (basically the same as ganged/unganged) I did not see anything like this either.

I did see "DIMM Interleave." and I tried both Enabled and Disabled (default was enabled).

During the boot memory test it is reporting 128bit so this leads me to believe it is running in ganged mode.
 
#18 ·
DFI Mobo's can be selective about RAM compatibility but it is odd that the two matching sticks won't work together. Try the new RAM pair in the PC that the Buffalo came out of.
 
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