memory upgrade for a 20 inch imac 2007

It can take 6GB of RAM; buy a 4GB module from a source such as Crucial or OWC.

(126961)

Crucial does not sell the special 4GB module required. I would only trust OWC as they test everything in Macs:

http://eshop.macsales.com/item/Other%20World%20Computing/5300DDR2S4GB/

However, note you pay a high price per GB for this special module

As Neil suggests with one tiny addition. Replace one of the two 2Gb modules with a 4Gb module with care; they are sometimes a tight fit. If you are in the UK Crucial are your best bet and they will send you instructions with the order and talk to you, one to one, on the telephone. I have the same machine as you with 6Gb running happily.

rkelley712 wrote:

was told by Crucial that it only can go to 4GB

That is because, for the most part, Crucial sticks with Apple's original and often outdated RAM specs. Many Mac models can, with newer and larger RAM modules developed after Apple engraved a machine's specs in stone, safely handle more RAM. Crucial does recognize these for some models but not all. That's why I gave you the OWC link. OWC has been in the forefront of testing and evaluating newer models for compatibility in all Mac models.

When I search the Crucial U.S. site for the required module:

4.0GB PC5300 DDR2 667MHz 200 Pin

I get hits for only smaller modules.

We don;t know where you are but OWC, although a US-based company, ships to many overseas destinations. OWC are Mac specialists--that's why they have been my only RAM vendor for over a decade.

es, they told me that too, but they should supply you. The UK branch supplied me though I seem to recall they did say they took no responsibility. Whether that would mean no guarantee, I don't know.

this may help:

iMac memory upgrades: iMac (20-inch, Mid 2007) &iMac (Mid 2007): Memory Specifications - Apple Supporthttps://support.apple.com/en-us/HT1423#three

Your max is 4GB, and need PC2-5300 RAM. It runs at 667Mz. I'm somewhat new to "only" having macs, (got rid of the last PC recently =), but from a strict hardware perspective, you can install faster memory (so long as it's still PC2, 200 pin memory *only thing that will fit*) but it will simply down-clock to the bus speed needs of the CPU. Sometimes faster (more modern) memory is cheaper then finding old RAM sticks.

Cheap: http://www.newegg.com/Product/ProductList.aspx?N=1052408745&Submit=ENE

Best (Apple): Oops! they don't sell it anymore... Apple normally goes for the higher quality, low CAS latency memory, CAS 4 is the best in your case (i'd just google/eBay)

Thanks for clarifying the Memory module number. But it is Apple that say 4Gb max and I understand 6Gb has been thoroughly tested by OWC, a well respected memory supplier. That amount has also been used by many, many contributors here (myself included) and I have never heard of a failure.

BTW, a 'cheap' option is always better avoided with memory.