Hi everyone! Quick question, One of my pc's has 2 512 sticks of pc2-4200u-444-10-a1. Can i add two more 512 sticks of pc2-4200u-444-12-a1? Well i know the motherboard can take it, but are the two compatible?

Heya SkootA,

The timing will just be adjusted automatically by the motherboard according to the memory stick itself. As long as both are 4200, you should be just fine.

This does not mean however that the memory will work. If the new sticks use a voltage that the motherboard doesn't like, it may not work. And sometimes, the memory just doesn't work with other memory if they are different brands.

But on paper, it should be just fine.