Question Details:

I'm looking to upgrade my RAM from DDR to DDR2 and I'm not sure if they fit in the same slot. How do you know if you can upgrade?

Answer:

DDR2 DIMMs are not designed to be compatible with DDR DIMMs. The notch on DDR2 DIMMs is in a different position than DDR DIMMs, and the pin density is slightly higher than DDR DIMMs in desktops. DDR2 is a 240-pin module, DDR is a 184-pin module.

You cannot use them in the same slot only if your motherboard is designed to have this capacbility. You should check its manual to see if supports DDR2.