I think......

.....that I have pretty much decided upon an iMac 20". What I want to know is the following (sorry about more questions)....

Is it possible to pop the back off of an iMac and upgrade bits like the Ram at a later date? I mean apple give you the option of doing this prior to purchase but is it possible to do it later? Also will this invalidate an warranty as it does if you take the side off of some pc's?

If the above is possible how many RAM slots are there and how much will each support?? i.e. My laptop has 2x RAM slots and each will support a max of 1GB RAM chips giving a total of 2GB of Ram.

The graphics card on the iMac - does this have the 128Mb of Ram built in or does it take it's 128Mb from the total Ram installed in the unit. i.e. 512Mb Ram total installed less the 128Mb in permanent use for the graphics card giving a total of only 384Mb of Ram available for applications to use. (if that makes sense??)
I only ask as I got caught out with this situation on my laptop and don't want to make the same mistake again.

Thanks all for your patience. Hopefully when I get a Mac I will be able to help others at some point.

Say_Cheese said:

.....that I have pretty much decided upon an iMac 20". What I want to know is the following (sorry about more questions)....

Is it possible to pop the back off of an iMac and upgrade bits like the Ram at a later date? I mean apple give you the option of doing this prior to purchase but is it possible to do it later? Also will this invalidate an warranty as it does if you take the side off of some pc's?

If the above is possible how many RAM slots are there and how much will each support?? i.e. My laptop has 2x RAM slots and each will support a max of 1GB RAM chips giving a total of 2GB of Ram.

The graphics card on the iMac - does this have the 128Mb of Ram built in or does it take it's 128Mb from the total Ram installed in the unit. i.e. 512Mb Ram total installed less the 128Mb in permanent use for the graphics card giving a total of only 384Mb of Ram available for applications to use. (if that makes sense??)
I only ask as I got caught out with this situation on my laptop and don't want to make the same mistake again.

Thanks all for your patience. Hopefully when I get a Mac I will be able to help others at some point.

Click to expand...

Yes, you can pop the back off to upgrade your computer. Your warranty is fine so long as it's just the RAM you mess with. There are 2 slots, each of which can hold a 2GB stick. The 128MB of video RAM are on the video card itself; it does not detract from your regular RAM.

It depends pretty much of which iMac you're going to buy...

The iMac G5 Rev.A and B where easy to upgrade: Popping of the back gave you easy access to everything, so it was easy to upgrade the memory, HD. Airport Extreme card if it didn't come with it and possibly the optical drive...anything else was part of the mainboard anyway, so not upgradable.

The iMac G5 with integrated iSight and the iMac with Intel CPU has only the memory as user serviceable part, through a small trap door at the bottom of the iMac bezel.
Memory config:
iMac G5 iSight 512MB on-board, one memory slot that can take up to 2GB DDR2-module.
iMac Intel no memory on board, 2 DDR2-SODIMM slots, up to 1GB each.

Trying to upgrade anything else is not recommended, unless you have some good experiences in dismanteling fiddly electronic devices (like for example laptops). And you will loose your warranty if you try to open the iMac (which, unlike the older ones, is not simply popping of the back).

The video memory is no shared memory like in cheap PCs, but dedicated, special memory, like on a separate graphics card. This goes for EVERY Mac, they never had shared video memory, not even the Mac mini or the iBook.

iMac 20"

The RAM capacity is 2g. Comes with 512 MB. It is easy to install through panel. The graphics card is 256 MB on it's own if I'm not misstaken.

^128mb video card, optional 256mb. 2 ram slots, each holding a maximum of 1gig.
A small panel on the lower bottom of the iMac allows you to upgrade the ram at your leisure.