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View Full Version : How much RAM does the G4 20" iMac really support?


Vinny
Oct 27, 2004, 12:04 PM
I've got a 20" G4 iMac that I'd like to install some more RAM. I ordered the iMac with 1 512MB stick in the internal slot and nothing in the user accessible slot. Can I drop in a 1GB stick in the user accessible slot for a total of 1.5GB? I don't see the specs for the 20" on Apple's website, but they say the 17" is limited (don't know why) to 1GB total RAM.

Thanks for any assistance!

Vinny

jsw
Oct 27, 2004, 12:09 PM
I don't see anyone offering a 1GB stick for the 20" iMac G4s. Apple said a max of 1GB, and the RAM sites don't offer anything bigger than 512MB sticks, so my guess is that you're stuck with 1GB.

rdowns
Oct 27, 2004, 03:10 PM
Supports up to 2GB of RAM, 2-1GB sticks. Apple even sells them.

Makosuke
Oct 27, 2004, 05:05 PM
Rdowns probably thinks you're talking about the G5 iMac, which does support 2GB. The G4 iMac you've got, however, maxes out at 1GB--I haven't found mention anywhere that it'll support more than that, even unofficially (the 20" is mechanically identical to the 17", by the way, other than the screen).

If you're desperate, brave, and have money to burn, you could always buy a 1GB SO-DIMM with the same specs and see if the memory controller will accept it (if it works, be sure to spread the word). Me, I'd just settle for the 512MB--1GB total isn't too shabby for most uses.

rdowns
Oct 27, 2004, 06:43 PM
Rdowns probably thinks you're talking about the G5 iMac, which does support 2GB. The G4 iMac you've got, however, maxes out at 1GB--I haven't found mention anywhere that it'll support more than that, even unofficially (the 20" is mechanically identical to the 17", by the way, other than the screen).

If you're desperate, brave, and have money to burn, you could always buy a 1GB SO-DIMM with the same specs and see if the memory controller will accept it (if it works, be sure to spread the word). Me, I'd just settle for the 512MB--1GB total isn't too shabby for most uses.

You're right. My error, I was referring to the G5 iMac.

Mechcozmo
Oct 27, 2004, 10:01 PM
The G4 iMac needs the smaller RAM profile. That is why you max out at 1GB.

The RAM controller should accept more than that...up to 4GB would be my guess, the physical limit. But I really don't know for sure.

It would make sense, because the RAM controller is a fairly standard part for a G4, and so there doesn't seem to be a reason why to change it to ONLY support 1GB max.

melonloco51
Oct 28, 2004, 09:04 AM
I have installed a 1GB SODIMM in the user accessible slot. have had no problems. Bought the stick from Outpost.com for $149 this summer.

Also, after you warranty expires you could remove the bottom casing and install a 1GB DIMM in the factory slot. Doing it before then on your own voids the warranty. Alternatively, you could take the imac to an authorized dealer and they can swap the factory slot's memory stick for you.

Makosuke
Oct 28, 2004, 05:28 PM
I have installed a 1GB SODIMM in the user accessible slot. have had no problems. Bought the stick from Outpost.com for $149 this summer.
Well, there you go. This doesn't guarantee 100% that it'll work in all iMac G4s, but the chances are good since it works in one. Can't honestly say I'm surprised, since a lot of Macs actually support more RAM than they're supposed to (once chip densities go up, etc).

There's a theoretical chance Apple could intentionally disable this in a firmware upgrade or something, but that seems unlikely to me and I can't remember ever hearing about them doing that before (other than the toucher RAM spec issues that often pop up).

By the way, melonloco51, have you reported your success to XLR8YourMac? I looked through their iMac reports section and was surprised I didn't find mention of anybody trying this, but I'm sure there are a lot of people who'd like to know.

Vinny
Oct 31, 2004, 01:43 AM
Melonloco51,

How much RAM do you have total in your iMac? How much appears in the system profiler?

-Vinny