RAM Upgrade Compatablity

[tokyotech]

I currently have 4 x 256MB DDR2 400 MHz sticks on SDRAM. I want to toss out two of them and replace them with 512 MB ones. My computer supports both 400 and 533 MHz models that are unbuffered and non-ECC. On www.newegg.com, some of the 533 models are cheaper than the 400 models. Should I go ahead with the 533's? I am aware that the 2 x 533's will run at the same speed as the remaining 2 x 400's. Will the 533's slow down my computer more than the 400's because they are incompatible with the two remaining 400's? I've been hearing mixed responses on whether ALL sticks of RAM in the computer must be the same or just pairs of sticks must be the same...

This is my system:
http://www.crucial.com/store/listparts.aspx?model=Dimension+4700+Series

For some reason, this page does not agree with my personal observations of the current RAM in my system, which are 4 of these: Samsung 256mb 1rx8 pc2-3200u-333-10-a1. PC3200 is not even listed on that site.

 

[chupacabra]

it "says" that it can support DDR2 6400 which would be good, but if you keep the old sticks it will downclock itself, i rather suggest you to buy either way 512mbs x 2 sticks or 1gb x 2 sticks, you can find them pretty cheap now.

2x1gb sticks
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231098

2x512mb sticks
http://www.newegg.com/Product/Product.asp?item=N82E16820231102

 

[tokyotech]

If I buy 2 x 512MB, can it run with my old 2 x 256MB without a problem?

 

[frost02]

if they're the same speed (400 mhz i believe) then yes, if you buy 533mhz sticks and put them with your 400mhz sticks then the 533mhz sticks will automatically downclock themselves to 400mhz. other then that yes they should work

 

[chupacabra]

If I buy 2 x 512MB, can it run with my old 2 x 256MB without a problem?

you can but it will reduce the speed to half and you won't see any difference in performance , your ram is running probably around 200mhz since it's DDR

 

[tokyotech]

No, my computer is DDR2, not DDR.

I am aware of the slowing down part, but some nerds on other forums said that ALL sticks of RAM in your PC should be the same size and speed for maximum compatibility. They said that mixed size/speed could crash the computer, even if you install in matching pairs but each pair is different.

http://www.techsupportforum.com/har...pply-support/156913-upgrading-ram-issues.html