older iMac- 2Gb of RAM or 2.5?

[m0nkeyb0y]

I'm upgrading my parents iMac, an older Intel 2.16 iMac. They have 2x512 Mb RAM. I know there's performance gained by using paired memory, but then I can only go to 2Gb. What's the tradeoff by just buying 1x2Gb and adding it to the remaining 512 stick? Suggestions?

 

[flopticalcube]

The gain is 5% at most. More memory trumps dual-channel.

 

[tomacintosh]

Max it out, 2GB and 1GB sticks! Not too costly