Does laptop RAM have to be paired?

[Unarmed]

Can I put a 512 and a 1 GIG in my Macbook or do they both have to match?

Thanks

[BiPolar_Nut]

I'm not certain, but the way I understand it DDR and DDR2 ideally should be matched to take advantage of the doubling of the data rates, but they could work mismatched at single data rate speed. I'm just going by hearsay tho, so Judge Judy would throw it out....but she hasn't been laid since 1973.

[guller]

Depends on the system. The easiest thing to do would be to go to crucial.com or pny.com and let them scan your system. In general most systems can use mixed, just make sure that you don't get a slower speed. If you get the slower speed the faster ram stick in your machine will run at the slower setting, faster speed sticks are ok. Try to stick to the same brand of ram, sometimes that causes issues.