System reboots. Faulty RAM

[goldeagle2005]

Hey fellow geniuses
I've got 2 RAM sticks
--> 512 mb @ 400MHz
--> 512 mb @ 333MHz

Here's the problem. When I install the RAM sticks individually one at a time, the computer starts up fine. But, when I install both of them, the BIOS gives me three long beeps(the code for bad RAM). If sometimes the RAMs do work together, the comp restarts just as the XP login screen appears. What do you think is the problem?

I kinda suspect the 333MHz RAM stick coz when I gave it to my friend to test, his comp kept rebooting.

I have also verified the 400MHz stick is fine coz when I used the comp with just that stick, it never rebooted

Correct me if I'm wrong, but if I install RAM sticks of different clock speeds, won't the system operate at the speed of the slower RAM stick?(in my case it should operate at 333MHz, and it does). What I want to know is can two RAMs of diff speeds conflict and cause the comp to reboot?

Earlier, I had 3 RAM sticks -- the 512mb/333MHz one, a 256 mb/266MHz and a 128 mb/133 MHz stick. This combo worked fine (altho with a speed of 133MHz) and the comp never rebooted.

Please do let me know what the problem could be. For further info, do let me know.

My system specs are as under:
AMD Athlon XP 2000+
MSI 6712 mobo ( http://www.msicomputer.com/product/p_spec.asp?model=KT4VL&class=mb )
NnVidia GeForce 4 MX 440 SE w/64mb DDR
80 gig seagate IDE
ASUS CD-RW+ASUS CD ROM

Thanks a lot in advance

[JANINE]

your right with what you've said that the system should run at the speed of the slower item.

it could be the RAM gone bad or a bad memory slot maybe but i'd also check to see the speed of your system isn't too much for the RAM. look at your FSB speeds. somebody i know had exactly the same problem as you've described and found the fsb to be too fast.

Also RAM types can play a big issue especially if you have incompatible types

[Catweazle]

The RAM is simply incompatible for working together. In theory your setup should work, but in practice when you mix and match different brands and types it often doesn't ;)

Best thing to do if you need 1Gb of RAM - sell both sticks as secondhand items and buy a pair of matched modules instead ;)

[goldeagle2005]

apparently the 333MHz module was at fault. It was still under warranty, so I got it replaced. Everything;s working great now. Thanks a lot for your support, Janine and Catweazle. I appreciate it.

[JANINE]

or just buy one 1Gb stick.

always willing to help and it good that you've finally sorted your problem

[dcc]

2- 512MB sticks will be faster.