Need to identify RAM Required - Dell OptiPlex GX280

vanauden used Ask the Experts™

I am trying to add RAM to my computer, but I am having trouble identifying it and ensuring that the motherboard RAM slots will support the new ones:

Computer model:  Dell OptiPlex GX280 (There is no "n" or "SF" or "SMT" that I can see)
Current RAM model:  Samsung M3 78T6553BZ0-KCC
On the RAM it is written: 512MB 1Rx8 PC2-3200U-333-10-A1
Currently installed: 2 sticks of 512MB
Slots on motherboard: 4 available

Did a search in Corsair web site RAM selector and came up with this option: VS1GB533D2 is an unbuffered, non-ECC, 1GB DDR2 memory module operating at PC2-4200

Did a search on Crucial site RAM selector and came up with this option: CT65713 1GB, 240-pin DIMM, DDR2 PC2-5300 memory module

What I need help with:

Can I put a 1GB stick in the slots on this PC?
Can I put a 2GB stick in the slots on this PC?
What is the maximum amount of RAM this PC supports?
If my original RAM is PC2-3200, why do the RAM selectors say I should use PC2-4200 or PC2-5300?
What is the best RAM I should use (not the brand, but the type)?

Can anyone help me?


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Go to and go to the RAM tab and it will ask you for your computer model # etc. It will determine what RAM you need and how much you can put in. It's a great and secure website that major companies use a lot.
Most Valuable Expert 2013
Both speeds are supported by the BIOS - try not to mix them :)
400 & 533 MHz DDR2 SDRAM non-ECC
Maximum of 1GB per strip - so on your 4 slot version maximum of 4GB


Wow thx for finding the info for me... I always find the Dell site a little hard to navigate.

It is greatly appreciated!
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thx guys


Actually, I just found out that Crucial's site is wrong.

This computer supports 400Mhz and 533Mhz memory according to the dell spec site.

This means :

400 x 8 = 3200 so the minimum is DDR2 PC3200 400Mhz
533 x 8 = 4264 so the maximum is DDR2 PC4200 533Mhz

Crucial's site says I should buy DDR2 PC2-5300 memory, which means 5300/8= 662 (= 667Mhz)

That is incorrect.

Corsair's site is right: It offered VS1GB533D2, an unbuffered, non-ECC, 1GB DDR2 memory module operating at PC2-4200

hmmmm, wow, that's the first I've ever seen crucial make a mistake. :(

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