Upgrading to more memory; different speed o.k.?

[MarleneD]

I'm running windows XP (Dell dimension 4700) and would like to upgrade my memory.  I currently have  512 mb DDR2 SDRAM at 400 MHz.  I'm interested in adding 2 GB running at 667 MHz (Kingston Technology PC5300 DDR2 DIMM).  Is this o.k. or possible?  Does adding memory running at a different speed mess things up?
Thanks

[blunder]

You will have to check the specs on the Mobo, and see what kind it will support. If you can let us know what kind of Mother Board u have i am sure someone here would be able to tell u if it will work or not.

[homer]

your motherboard will only support up to DDR2 533mHz. you can purchase DDR2 667mHz, but  it will not run at full capacity, it will run at 533mHz.

Does adding memory running at a different speed mess things up?

it doesnt "mess things up," but your machine will run much more efficiently with matching RAM. it would be best to simply remove your stick of 512mb and just run on the 2gb's as 2gb's is more than enough for that computer.

[MarleneD]

O.k. Homer, let me see if I'm understanding you correctly.  If I just remove the current modules (I think I have two 256 because they do work in pairs, right?) and install two 1GB in two different slots then my machine should run more efficiently but only at the max speed of 533 MHz and not the full 667 Mhz
that the modules are being advertised as, correct?
Thanks again.

[homer]

(I think I have two 256 because they do work in pairs, right?)

they work best in pairs but are sometimes not paired.

If I just remove the current modules and install two 1GB in two different slots then my machine should run more efficiently...

remove the old RAM stick(s) and place the new RAM sticks in the same slots. motherboards have color coded RAM slots, you want to place your two sticks in the same colored slots.

...but only at the max speed of 533 MHz and not the full 667 Mhz

that is correct. you may wish to purchase 533mHz RAM instead, it should be a little cheaper then 667mHz. no point in spending extra money on RAM that your computer cannot take at full capacity.

[MarleneD]

Thanks Homer for your advise.  I will hopefully find memory sticks/modules that run at that slower speed for 1GB.
Thanks a bunch

[homer]

Thanks Homer for your advise.  I will hopefully find memory sticks/modules that run at that slower speed for 1GB.
Thanks a bunch

your welcome