What ram does my dell optiplex gx280 p4 ht take

[Fish-N-Fool]

The info on my puter is; Dell Optiplex gx280 p4 3.4 Ghz with 2.0 Ghz of ram and a 150 Gig HD. I want to put 2 more Ghz of ram in it. I know it uses DDR2 ram but not sure what else I need to know to buy some. Does it use the PC4200 or the PC2-5300? I see there is PC6400 too? gees why can't they make them all the same. And what about the Mhz? I see they are 667or 800 Mhz I see some good deals on ram online and need some help on what to get.
Tnx for any help.

 

[GhislainG]

Why not download CPU-Z and use it to check what RAM is installed? Look at both Memory and SPD tabs. On the SPD tab, you can check each slot to see what it contains.

That system should use DDR2-533 memory (266 MHz in CPU-Z Memory tab), e.g., Crucial CT657134.

 

[truegenius]

+1 GhislainG

also read this
support.dell.com/support/edocs/systems/opgx280/en/ug/smtindex.htm

 

[truegenius]

+1 GhislainG

also read this
support.dell.com/support/edocs/systems/opgx280/en/ug/smtindex.htm

 

[vickimichelson]

do what truegenius says, done exactly the same today lol !!!

 

[Fish-N-Fool]

Best answer selected by Fish-N-Fool.