RAM upgrade help

[games130]

I am helping my friend choose a RAM as he wants to upgrade it 1Gb. He already has a 512mb installed and the RAM his motherboard can support is up to DDR 400/PC3200. What he wants is to add another 512mb of RAM. I was abit concern so can you guys help me out with a few doubts that i have:-

1.) How would i know if it is compatible with the pre-installed RAM. What are the factors involve?
2.) I saw that scan has a 30 pound 512 CL2.5 RAM for sale, if the pre-installed RAM is a CL3.0 what will be the CL speed of the two RAM when installed?


Thanks

[nvening]

the ram modules will work independantly of each other (as far as i know lol), its only in dual channel where they work together and so have to be the same.

You need to cheack how much ram his pc can take and how many slots he has free, use the memory configurator (and indeed buy thier good quality RAM if you want) and www.crucial.com/uk

[Thorsson]

Theoretically you can mix modules, as long as you run them at the slowest speed. However I have found in the past that sometimes different modules just don't get on with one another.

Also you need to check that the configuation is supported by the motherboard (but I'd be very surprised if it didn't support 2x512Mb).

[NightshadowUK]

I saw that scan has a 30 pound 512 CL2.5 RAM for sale, if the pre-installed RAM is a CL3.0 what will be the CL speed of the two RAM when installed?

Unfortunatley both would run at CL3, even with non-dual channel RAM, they have to share speeds. Just like if you got PC2700, the original would downgrade from PC3200 to the slower speed of the new stick.