# Mixing CL2 & CL3 RAM



## K-B (Oct 24, 2005)

Hi, I have a system (not the one in my profile) it is a PIII 450mhz, and it had 256 SDRAM, (2x 128 and one free bank) and I bought a Simpletech 128 meg SDRAM to add on. However, the SimpleTech is CL3 while the current RAM is CL2. I read an article that said that it's ok to mix them. Well, it is detecting 384MB in BIOS, so I thought it's all OK. But XP will boot past the splash screen, then right before it says "Loading Personal Settings" or something like that, it flashs a BSOD very fast, and restarts. I removed the new stick of RAM and it started up fine, however it said "Windows has recovered from a serious error". 
I can't find the motherboard model, it's an Intel board, computer is a Gateway model TBR 450 PIII. Is there anything else to try, or is the RAM I got no use for this computer? Thanks.


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## blackduck30 (Sep 7, 2004)

I dare say that it will be a incompatability issue, mixing different brands of ram is always a hit and miss affair. I recently put a 256mb stick of ram into my daughters computer and removed all the others smaller sticks, the 256 showed up as 32mb but worked fine along side a 128mb stick in another computer


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## Kalim (Nov 24, 2006)

Have you tried only using the CL3 RAM alone?


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## K-B (Oct 24, 2005)

Ok, thanks for the replies. I would have replied sooner, but I was typing out a message a couple hours ago, and the computer restarted under my feet. 
But this is what I did. I downloaded Windows Memory Tester and burned it to a CD, and booted to it, with all 3 modules installed. It got stuck on test 6 of 8, giving a Trap 00000006 Exception error, and a long list of errors. So I shut the computer off, removed the new CL3 module, and booted to the test CD. It completed all tests without incident. Then I shut the computer back off, removed the 2 old modules, and installed the new CL3 module, alone. Booted to CD, ran all tests without incident. So I shut the computer off, and rearranged the modules in different slots from the original failed setup. Booted to the CD, ran all tests without incident. Great, I thought. So I removed the disk and booted to Windows. And a split second after the splash screen disappeared, a BSOD once again flashed across the screen. DUH. I restarted, and this time it booted with no incident! I logged onto TSF, was half way through typing a message when the computer flashed a BSOD and restarted. 
Yeah, I guess it must be incompatibility. Yet when the computer POSTs, it counted up all the RAM to a total of 384. FYI, all 3 modules run on the same frequency, 133mhz.


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## twajetmech (Jul 1, 2004)

Depending on the mobo if you put the memory with cl3 in the first memory slot, that will set the timings for the other two modules and your timing instability should be solved also if you have the option in the bios, bump the memory voltage up a tad


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## Kalim (Nov 24, 2006)

I usually get no problems putting mine from CL 2, 2.5 to 3 in the BIOS.


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## twajetmech (Jul 1, 2004)

If I'm not mistaken the pIII 450 was a 100mhz cpu not 133mhz, at least the one in my old system was, try setting the jumpers or bios settings to run at that speed.


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