Exactly what kind of RAM do I buy to upgrade from 2 to 4gb in 3.06ghz iMac?

[qor1979]

So I've found RAM on Newegg.com but don't know the exact kind to buy. I want to save when I buy my iMac by keeping the original 2x1gb sticks in it and buying the 2x2gb sticks elsewhere. I know it must be 800mhz DDR2-SDRAM PC2-6400. Other than that, what brand should I buy? I've found some for around $80 which is much cheaper than the $200 Apple charges for the upgrade.

Hold on, now I found something called "Fully Buffered" memory for Macs on the same New Egg site. They sell for more than the memory upgrade from Apple. What gives? Is the cheap stuff worth the savings? Is this more expensive FB stuff worth the extra money?

What about Kingston 4gb DDR2 800 (PC 6400) Dual Channel Kit Memory for iMac? KTAMB800K2/4GB $82.69 free shipping.
Sounds good but will it work as well as factory installed Apple 4gb?

And then what do I do with the old memory?

 

[davidosus]

My suggestion is to download...

http://www.crucial.com/systemscanner/MacOS.aspx

This small application will tell you exactly what kind of memory you have installed, how much of it you have, and how much your computer may take.

With this information visit your local store and buy the required memory.

 

[hughvane]

So I've found RAM on Newegg.com but don't know the exact kind to buy. ... Other than that, what brand should I buy?

Check your Mac specs at http://www.everymac.com from where there's a link to OWC which sells Mac-specific RAM, or go straight to http://eshop.macsales.com/

In addition to Crucial, which a number of Mac users recommend, Kingston is a reputable brand which I've used without trouble in various Macs. Most advice says "matched pairs", and your iMac has only two RAM slots, so your most logical choice is 2 x 2 Gb matched sticks.

And then what do I do with the old memory?

Sell them, or keep them as 'just-in-case' backups.