Replacing DDR2 400Mhz ram

[SamRand5]

Hello. I am trying to upgrade my ram. I have 4 slots. 2 are empty. Currently it runs on 2 sticks of 2GB DDR2 400Mhz. I wanted to just double it by adding what I already have in there but I guess the 400Mhz speed DDR2 ram is beeing phased out because I could only find one type of ram that speed and it was 2 sticks of 1GB ram. I know I can't jump up to DDR3 but if I do away with what I'm currently running on can I upgrade to DDR2 1066Mhz ram?

Also, I found this odd. I ran Speccy on my computer to find out what I have in there. Websites and forums are telling me that DDR2 400Mhz is PC2-3200. However, Speccy tells me that my sticks are PC2-6400. I don't really understand what the PC is about. However is seems that most PC2-6400 ram is DDR2 800Mhz. Does this mean that my 400Mhz might be able to run with 2 other sticks of 800Mhz DDR2? If so, do all the sticks need to be the same number of GB?

Also, if I did just go with the 2 1GB sticks of DDR2 400Mhz, can that run with the ones I already have in there even though they are different number of GB?

Thanks for your help!

[webrocky]

Firstly you need to check the specification and features of the mother-board of your pc. If it can handle the ddr2 1066mhz ram then you can replace and upgrade into ddr2 1066 MHz frequency ram. But please don’t mix the 400 MHz ram and 1066 MHz during installation. If you mixed it and install it then your computer wont boot and problem occurs.

[rubberman]

If your mobo supports ECC ram, here is a link for 2x2gb sets from buy.com: http://www.buy.com/prod/4gb-kit-2-x-2gb-memory-for-dell-precision-workstation-670-pc2-3200r/234073551.html

Also, your operating system needs to be able to handle more than 4GB of ram. It will either need to be a full 64-bit OS, or supports the extended memory model to handle more than 4GB (applications will still only get 4GB or less each).

[hazzag1995]

Crucial will tell you what you got, and what u can upgrade to. Head to www.crucial.com and use their system scanner.