View Full Version : iMac G4 memory question
Nov 20, 2004, 01:13 PM
I have a 17inch 1GHZ G4 iMac and I am trying to figure out if I can/should put more memory in it. I have 768 megs of ram now, and i would like to have the full 1gig of ram. Obviously I have a 512 and a 256 in now, but I want to figure out which size is in the user accessible slot on the bottom of the computer. If it is the 512 thats in there then I can't really upgrade with out messing with the fatory one which i wont do. I know i could just take the bottom off and look, but I'm at school now and don't really feel like doing that until i get home for thanksgiving. I looked in the systemprofiler, and it shows the two memory sticks in my computer, 512MB in slot DIMM0/J22 and 256MB in slot DIMM1/J20. I was just wondering if anyone could tell me from those slot numbers which on is the upgradbale one.
Nov 20, 2004, 02:23 PM
Did you order this iMac with 768MB of RAM from Apple? If not, how much of it was from Apple? The iMac G4's generally have 256MB built-in that cannot be taken out without voiding the warranty. If that is what it came with (and you added 512 from a 3rd party) then you will have to buy a 1GB stick to get it over a GB RAM.
Click on the Apple in the top left of your screen and select 'about this mac'.
Then click on 'more info...'
the first slot will be your non-upgradeable RAM (that one stays in).
the 2nd will be what you can take out and add to.
Nov 20, 2004, 03:00 PM
Ok, i'm not sure exactly what came in mine, but i know from lookign at some stuff that the iMac's then came with 256 standard. I got this in june of 03 as a grad present so my dad had ordered it from macwarehouse, because he works for a fairly large commercial preinter and they had some discount. But at the time, as macwarehouse usually does, they had a buy the computer, get free ram. I'm not sure wheterh at the time they offered 256 free or 512 free, but if what you say is correct about the order of the slots in the system profiler (first listed is non-replaceable, and the second is replaceable), then mine actualyl came with 512 in it and 256 was added by macwarehouse. (listed as DIMM0/J22: 512MB, DIMM1/J20: 256). If that is the case, then i should be able to just buy another 512 stick.
Thanks for the help, and by the way, im very jealous of all the stuff you have listed in our signature! It must be awesome having a new G5 iMac and a new powerbook. ;)
Nov 20, 2004, 03:14 PM
Unfortunately, you're kinda stuck. DIMM1/J20 is the built-in memory, and DIMM0/J22 is the user accessible slot. DIMM1 is a normal-sized memory stick like you'd find in a desktop machine, and DIMM0 uses notebook-sized memory.
On the positive side, you CAN replace the internal memory with a Philips head and #10 Torx screwdrivers and some care in about 10 minutes, but it sure helps to have been inside of one before. A decent Mac-oriented retailer could probably do it for you, and the desktop ram will be $75 or so (less whatever credit they'd give you on the 256 Meg DIMM) to upgrade to 512 Megs.
I do have to say, though, that I don't think I could tell the difference between 768 MB and 1024 MB on my 17" iMac. Unless you're deep into Photoshop or digital video, you'd be hard pressed to tell the difference. I have the identical configuration that you have, by the way.
Nov 20, 2004, 03:32 PM
Ok, i had figured from the start that that might be the case. If there realyl wouldnt be much of a difference, I guess thres realyl no point, as im not that heavy into photoshop and other stuff like that. thanks for the help
Nov 20, 2004, 04:20 PM
I also have a 17" with 768. I never feel a need for any more RAM, but that's just me. Most likely the 512 was added to the user-accessible slot, as I did with mine.
Nov 22, 2004, 01:51 PM
You could always try to sell the 512MB stick in the marketplace (here on MacRumors) or on eBay and then buy a 1GB stick. I'd say you could get around $75 (maybe more) for a 512MB stick for iMac G4's and then you'd pay around $200 for a 1GB stick (go to ramseeker.com)......so it would probably cost you around $125 to get your iMac to 256MB + 1GB.....which would be more than enough for what you said you do.
Dec 8, 2004, 03:43 PM
Yes, you have the 256K in the internal slot, same as I do. The replacement cards are located at:
Replacing the internal isn't too complicated, as per the discussion above.
I think it is bogus that Apple doesn't offer the internal cards for sale. Their sales rep was equally surprised when I called them about it.
I also have an eMac with the 1GHz processor. Good machine. I use it for digital video and need the 1GB memory. We just got the iMac and planned to swap hard drives (we currently have a 160GB in the eMac and an 80GB in the iMac), but because of the difference in memory we'll have to wait, because I won't do video on a machine running only 256MB.
When you're doing what you consider "heavy use" on your computer, open the "Activity Monitor" program in your utilities folder. From that you can see what is using your system resources and get a better idea whether you're using all your memory. When I'm rendering video on the eMac, I typically see that over 80% of the system memory is in use, which means that a 768MB memory would not be enough (a slow process would become even slower). Chances are you won't need the extra memory unless you're doing video work.