You want to stick with PC-3200 DDR2. If your machine takes DDR2, the slots are different than plain old DDR RAM, so you cannot simply throw in a stick of DDR RAM. If you buy something slower than the current speed, both RAM modules would use the slower speed. For example, if you have the PC-3200(400MHz) chip and a PC-2700(333MHz) chip, both would run at 333 MHz.
Depending on the motherboard, sometimes you can use sticks of different capacities. Some computers require you to install RAM modules in pairs of two equal capacity chips. Some motherboards really don't care. In your case, it looks like another stick of 512MB would be fine.
The best place to look is the manual. Try and hunt around for a motherboard manual, it will tell you any specific rules the motherboard has for RAM instalation. Also, newegg is normally much cheaper than Best Buy, and I have never had a bad experience with them.
I just bought a Dell XPS M140. I chose not to upgrade the ram do to the fact that I work at BestBuy and can get Ram for cheap (and theres always newegg too). Anyway, I want to upgrade am not sure what to get. Here are the specs for my unit:
* RAM installed size
* 512 MB
* Max supported RAM
* 2 GB
* RAM Technology
* DDR II SDRAM-400 MHz and over
* Memory specification compliance
* RAM / Configuration Features
* 2 x 256 MB
So my questions are...
Do I have to stick with PC2-3200?
Do I have to use DDR II or can I use DDR?
I know I cant combine the DDR and DDR II but can I use, say a 256mb DDR II chip and a 1gb DDR II chip?
What do you guys suggest?