Pulling Old Ram From Dell Inspiron 530 And Installing In Dell Optiplex GX280

[JASII]

I recently pulled two 512 MB memory sticks from my Dell Inspiron 530. They are Samsung PC2-5300U DDR2-667 512MB M378T6553EZS-CE600. Anyway, my mother in law has an old Dell OptiPlex GX280. According to Crucial Computer memory upgrades for Dell OptiPlex GX280 (Desktop and Mini-tower Models) Desktop/PC from Crucial.com the Memory:
DDR2 PC2-5300, DDR2 PC2-6400

Memory Type: DDR2 PC2-5300, DDR2 PC2-6400, DDR2 (non-ECC)
Maximum Memory: 4GB
Slots: 4
Each memory slot can hold DDR2 PC2-5300, DDR2 PC2-6400 with a maximum of 1GB per slot.*

But, I had her do a scan and she has one 256MB DDR PC2-3200 and one 512MB DDR PC2-3200.

My questions are:

-Are the old Samsung sticks compatible for her Optiplex? ( I think they are.)

-Since Crucial states "Although the memory can be installed one module at a time, the best performance comes from using matched pairs of modules." Should I simply remove her old sticks and replace with the two matching 512 MB sticks?

-Or, could I leave what she had and simply add the two Samsungs?

-Will the "new" Samsung" memory sticks speed up her computer?

 

[kb0nly]

I would remove the memory she has and put in the matching sticks you have, they will work in the optiplex, i have dealt with them more than a few times.

If you mix them, leave her 512 3200 and put in your 512 5300, the computer will run at 3200 as it will only go as fast as the slowest stick in the system, the faster stick will be run at the lower speed.

You won't see a huge increase in speed due to the memory speed, but where you will see the biggest improvement is increasing the memory amount available. If you got some 1gb sticks and put them in then it would really speed it up. I have got into those old optiplex's and put in 2gb in place of the stock 512 it had and what a huge improvement, the owner cant believe it most of the time.