4.5GB RAM on iMac G5 (isight) ?

According to [this page|http://www.everymac.com/systems/apple/imac/faq_g5/imac-g5-processor-upgrad e-ram-and-hard-drive-upgrade-pci-slots.html#ram], 2.5GB is the limit.

Give it a try and let us know 😉

You will only be able to use 2 GB of the module, since 512 is soldered to the logic board, and it might cause problems, Macs are very fussy about their RAM.

I would give it a pass and get the correct stick.

The machine will not recognize more than 2.5GB. Since 512MB is soldered to the logic board, you can only add 2GB for a total of 2.5GB. I'm not sure how I can make it any clearer. *A 4 GB stick will only be recognized as 2GB, because there is already 512MB in the machine!*

Tenacious, aren't you? The reason is the architecture of the G5 only permits recognition of 2.5GB and because Apple says so!

Any chance of posting a screen grab of the Apple tab with the computer specs? Just for the sceptics reading!

... and one more thing. If you look at the system monitor, is OS X really using all the memory or is it stopping at 2.5GB?

Message was edited by: PJB

According to Apple themselves, your Mac supports up to 2.5 GB or RAM. You can put in a larger stick, but you will not be able to use the whole thing. It's the same as putting faster RAM in than your computer is designed for. The RAM will not run at its rated speed (example, PC133), but rather it will slow down to the bus speed of the system board. You can't force the hardware to accept more than it's designed for.

http://support.apple.com/kb/SP40

What kind of RAM is that? I'd like to try it out as well

nicolas mbp problem wrote:
The G5 architecture supports way more than 2.5 gigs (example, powermac G5s), Apple said it would support only 2.5GB because when the imac G5 came out, the 4 gig modules didn´t exist, now they do, and they work great.

Same thing actually happened with the first gen. aluminium powerbooks. AND the first gen. intel Mac PROs...

Careful, you're drawing assumptions.

Try installing 4GB of memory on the first generation of MacBooks and MacBook Pros. It won't work. Whereas with your iMac the most logical explanation for the documented 2.5GB limit is because hardly anyone had tried to install 4.5GB until now, this does not hold true for all models. Users have been trying to install 4GB of memory into original MacBooks and MacBook Pros for years now, and it doesn't work due to hardware limitations, meaning the documented limits in these cases are accurate.

It is in fact correct to say that you can't force hardware to accept more than it's designed for, and it is prudent to differentiate between what hardware is designed for and what the documentation says.

Message was edited by: Duo