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How do I get 1GB in my iMac G4?

Superdrive

Superdrive

macrumors 6502a
Original poster
Oct 21, 2003
772
56
Dallas, Tx
Hey everyone, as my computer ages, I feel the time has come to move from 512MB of RAM to 1024MB. In my iMac G4 800, I see the max is 1024. How do I get it to that amount? With 256 on board, wouldn't it be 1.25GB max or am I totally off on how this is installed? Normally I can google my way through anything, but this one has me stumped. Thank you for you help.

-TJ
 
I think these are the specs. for your computer.

Try Crucial Memory and go trough the steps.
The only offer a 512 for your mac, though they state it can do 1gb, which means that they arn't offering a 1gb DIMM.

NewerRam.com (Pricey, but good) states the same, and dosn't offer a single 1gb DIMM. Look here.

Another site I havn't used www.4allmemory.com states that 1gb is the max, 1 slot avalible for your computer, and they don't offer a 1gb DIMM.

Call Crucial or NewerRam, their people should be able to tell you what to look for at auction sites if they can't offer it now. (Ask them, What was the part number and specs.)
 
Thanks everyone, so I am guessing that my true max could be 1.25gb instead of the quoted 1gb? Or is there a such thing as a 768mb chip?

Thanks again,
TJ
 
You have to replace the lower slot [factory installed] stick (256MB) with a 512MB stick. Not for the faint of heart, and I suggest you wait until you're out of warranty (which you probably are now).
 
Superdrive said:
Thanks everyone, so I am guessing that my true max could be 1.25gb instead of the quoted 1gb? Or is there a such thing as a 768mb chip?
Click to expand...
Nope. Ignore all the advice that you can install a 1 Gb module - your machine takes a PC133 SODIMM and there is no such thing as a 1 Gb PC133 SODIMM.

Your maximum is 1 Gb with 2 x 512 Mb. There is a user-replaceable SODIMM, and an internal DIMM. As Yellow said, to get to 1 Gb you have to replace the internal DIMM, which is normally a service-shop-only replacement.

Your easiest move is to put a 512 Mb SODIMM in the user-installable socket and be happy with 768 Mb total. If that's not enough, consider upgrading the machine rather than the RAM.

Thanks
Trevor
CanadaRAM.com
 
Anything inside there it isn't exactly user replacable. I am not sure if I am daring enough to get in yet. The good lord knows it could use a cleaning though.

So, the 512 isn't soldiered to the mobo? I could always go big and put in two 1GB sticks. This will be the final update to my iMac G4, so I am just trying to figure out what to do. My other TiBook just hit its fourth b-day and needs some loving too, I might even go HD and RAM on that one. Thanks again for the help everyone.

-TJ

Edit: So there goes the 2gb option. I work as a computer service tech for the Geek Squad, so I can get inside there as a 'service shop' guy. I just need to figure out all the glue and other fun. Has anyone here done it before??
 
Questions before upgrade...

In my internal slot, it takes 168pin SDRAM. I can I install a 1GB stick here and have a 1.5GB max? I figure, if I am going to be inside the computer, I might as well go for the gold. Right? :)
 
You keep saying you're going to put more than 1GB in. If it says 1GB Max ram, you'd better stick with that if you don't want to run into trouble later on.
 
Superdrive said:
In my internal slot, it takes 168pin SDRAM. I can I install a 1GB stick here and have a 1.5GB max? I figure, if I am going to be inside the computer, I might as well go for the gold. Right? :)
Click to expand...

Read the posts, dude: The iMac G4 700 and 800 do not take a 1 Gb module of any description. They use PC133 SDRAM, the maximum is one 512 MB SODIMM in the accessible socket, and one 512 MB PC133 DIMM (yes, a different type) in the internal tech-only socket. There is no soldered-on RAM.
 
Lol. He keeps saying himself that it takes 1GB max and then saying "I'm putting 2 1GB sticks in" and "I'll get it up to 1.5GB".

I'm not trying to sound annoying, but for the sake of the computer, listen to the max ram!
 
CanadaRAM said:
Read the posts, dude: The iMac G4 700 and 800 do not take a 1 Gb module of any description. They use PC133 SDRAM, the maximum is one 512 MB SODIMM in the accessible socket, and one 512 MB PC133 DIMM (yes, a different type) in the internal tech-only socket. There is no soldered-on RAM.
Click to expand...

I read the posts and inquired about the 168pin DIMM in the internal slot. Simply my question is, the RAM will fit, what forces the machine to reject it if there is physically that much there? 1gb DIMM and 512mb SODIMM is that clear?
 
Superdrive said:
I read the posts and inquired about the 168pin DIMM in the internal slot. Simply my question is, the RAM will fit, what forces the machine to reject it if there is physically that much there? 1gb DIMM and 512mb SODIMM is that clear?
Click to expand...
Every Mac has a memory controller, which can recognize memory chips up to a certain number and a certain density. A module with a larger number of chips, or higher density of memory rows and columns on the chips, will not be recognized. Either it will fail to boot, or it will ignore the module entirely, or it will only use the first 512 Mb on the module.

Simply put, the machine's memory controller cannot count that high.

Your other problem is that nobody makes a 1 Gb PC133 module. Machines moved on to DDR memory from SDRAM memory before motherboards were developed that could read a 1 Gb module.

But why should I bother explaining, you haven't believed anything else I have written anyway.

Plonk.
 
CanadaRAM said:
Every Mac has a memory controller, which can recognize memory chips up to a certain number and a certain density. A module with a larger number of chips, or higher density of memory rows and columns on the chips, will not be recognized. Either it will fail to boot, or it will ignore the module entirely, or it will only use the first 512 Mb on the module.

Simply put, the machine's memory controller cannot count that high.
Click to expand...

Thanks, that was the info I needed right there.

CanadaRAM said:
Your other problem is that nobody makes a 1 Gb PC133 module. Machines moved on to DDR memory from SDRAM memory before motherboards were developed that could read a 1 Gb module.
Click to expand...

http://www.crucial.com/store/partspecs.Asp?IMODULE=CT128M72S4R75


CanadaRAM said:
But why should I bother explaining, you haven't believed anything else I have written anyway.
Click to expand...

Draw your own conclusions, but I appreciate the answers you provided. This is just the info I was looking for.
 
Superdrive said:
Thanks, that was the info I needed right there.



http://www.crucial.com/store/partspecs.Asp?IMODULE=CT128M72S4R75
Click to expand...

Thats ECC RAM. ECC RAM won't work on any Mac except the new Xserve G5's. Even if it did work, usually you can't mix non ECC and ECC RAM.

The highest PC133 DIMM you can buy is 512 MB for both the 168 PIN DIMM, and the 144 PIN SODIMM.

If you just buy a 512MB SODIMM for the user slot, you will see a noticble difference with 768MB total. You'll never use 1GB of RAM, I gaurentee it.

Also, iMac G4's aren't the easiest thing in the world to take apart. You have to be really careful when doing so. Also, when putting it back together you have to put thermal paste on the heat connectors near the outside of the dome or else it won't cool properly once you get it back together. Also, if its apart long enough, you have to replace the heat pads which is something you can't do because only Apple Techs can get them. iMac G4's don't have a heatsink on the processor itself, but rather heat pipes that circulate cool air through them. I think the only thing that has a small heat sink on it is the system controller chip. If you don't know what you're doing, then its not worth spending the time and money doing it you're self and risk making your iMac unusable. If its still under warranty then opening up the dome will void the warranty.
 
Will I lose data if I upgrade memory on my imac G4

I have an iMAc Power PC G4. 17' inch screen at 1.25 Ghz with a total of 512MB. The internal memory is 256 MB and before I got it they installed 256 more in the "user" slot at the factory. Now I just switched to Leopard and want to increase my memory. First, question: if I remove the the card in the "user" slot will I lose any data I have stored? I am thinking I might just replace the 256MB with a 512 MB. Or does it make more sense to remove both cards and have a 1GB installed internally? Again will data be lost by doing this?
 
Thanks everyone

Thanks to everyone who contributed to this thread. This was the top hit when I googled "Max RAM G4 iMac." Believe it or not, this is still useful info. With the tough economic times I can't convince my folks to buy a new computer and it's just dog slow with 10.5.
 
Seeing as this was revived a short time ago, I figured I'd ask here instead of a whole new thread - it had the right title.

I want to see if I can up my ram, but I'm in a different boat than the first user. I have a 1.25ghz iMac with factory 512mb ram - nothing in the user slot.

My questions are these:
1) Is there or is there not a 1gb stick that I can put in the user slot; if so where can I get it cheapest?
2) If not, where can I get the cheapest 512bm stick?

I've never shopped for ram, but know enough not to trust Apple for the greatest bargain. Who should I go with?
 
SkippyThorson said:
Seeing as this was revived a short time ago, I figured I'd ask here instead of a whole new thread - it had the right title.

I want to see if I can up my ram, but I'm in a different boat than the first user. I have a 1.25ghz iMac with factory 512mb ram - nothing in the user slot.

My questions are these:
1) Is there or is there not a 1gb stick that I can put in the user slot; if so where can I get it cheapest?
2) If not, where can I get the cheapest 512bm stick?

I've never shopped for ram, but know enough not to trust Apple for the greatest bargain. Who should I go with?
Click to expand...


Try looking here to find cheap ram
 
SkippyThorson said:
Seeing as this was revived a short time ago, I figured I'd ask here instead of a whole new thread - it had the right title.

I want to see if I can up my ram, but I'm in a different boat than the first user. I have a 1.25ghz iMac with factory 512mb ram - nothing in the user slot.

My questions are these:
1) Is there or is there not a 1gb stick that I can put in the user slot; if so where can I get it cheapest?
2) If not, where can I get the cheapest 512bm stick?

I've never shopped for ram, but know enough not to trust Apple for the greatest bargain. Who should I go with?
Click to expand...

This thread oughta answer your other questions:
http://discussions.apple.com/thread.jspa?threadID=1429312&tstart=77
 
just stumbled upon this thread via google. maybe one of you can help me with a question in this same vein?

i just bought 512mb of RAM and installed it in my computer. my specs previously read:

Machine Name: Power Mac G4
Machine Model: PowerMac3,5
CPU Type: PowerPC G4 (2.1)
Number Of CPUs: 2
CPU Speed: 1 GHz
L2 Cache (per CPU): 256 KB
L3 Cache (per CPU): 2 MB
Memory: 512 MB

and now read:

Machine Name: Power Mac G4
Machine Model: PowerMac3,5
CPU Type: PowerPC G4 (2.1)
Number Of CPUs: 2
CPU Speed: 1 GHz
L2 Cache (per CPU): 256 KB
L3 Cache (per CPU): 2 MB
Memory: 768 MB

is there a reason this doesn't add up right? could it just be that the memory i bought was in fact 256mb though it was clearly labeled 512?

thanks..

 
Take a look under

 -> About This Mac -> More Info -> Memory

What modules are listed?

(Also I'm glad I checked the date of the original thread. I was about to post that I was pretty sure all iMacs G4 were out of warranty.)
 
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