Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I recently got a pair of old Power Mac G4’s, but they did not come with RAM. I am trying to find out their memory specifications so that I can add some, but unfortunately I cannot find them.

Having little experience with Macs (or pre-built computers in general), I was a little surprised to see that they come in a fairly large number of configurations (I had thought that Apple simplified electronics by limiting the number of variations and/or that different configurations would have different model numbers). (Even these two are different from each other; they have different video-cards and motherboards, one has a modem the other doesn’t, etc.)

It looks like the G4 can have a wide variety of memory options, so I can’t figure out what kind of RAM to use.

Where can I find out the RAM support? I need to know the type (SDRAM, DD1, DDR2, etc.), the speed, and the size (both per-slot and system-total).

share|improve this question

Check with Apple:

Power Mac G4: How to Differentiate Between Models

According to that, the RAM configuration is most likely one of the following:

  • PC 100 SDRAM up to 1 GB

  • PC 100 SDRAM up to 2 GB

  • PC 133 SDRAM up to 1.5 GB

share|improve this answer
That looks promising, however it doesn’t account for the vast number of variations. These two in particular have EMC #’s of 1832 and 1843, but even those sub-models seem have multiple configurations. Are the four models on the Apple page generic configurations that all the other ones fall into? That is, do the limits for those four apply to all of the sub-(sub-?)models? – Synetech Aug 30 '12 at 2:17
Also, it says nothing about per-slot maximums or combinations. Some can be derived to some extent, for example 2GB max divided by four slots = at least 512MB per slot, but that doesn’t mean it cannot support a 1GB stick. Worse, how do you divide 1.5GB by four slots? – Synetech Sep 1 '12 at 20:01
1.5GB = 2x 51MB2 + 2x 265MB. :) The trick is going to be finding good PC133 RAM. I don't think there was anything larger than 512MB stick made in PC100/133. – Ƭᴇcʜιᴇ007 Sep 1 '12 at 22:24
> 1.5GB = 2x 51MB2 + 2x 265MB. Huh? I’m trying to find out the per-slot maximums. Are you saying that the 1.5GB model’s motherboard supports upto 512MB in two of its slots and up to 256MB in the other two? I have never seen such a bizarre thing, and even if that were the case, it would be all the more necessary to find out the specs so that the right sticks are inserted in the right slots. As for sourcing, that’s what Kijiji/eBay classifieds are for. – Synetech Sep 2 '12 at 0:01
You've never seen different sized RAM sticks in one computer? You mustn't have been doing this long. ;) Dual and triple channel don't apply, so in general you put the "lowest (capacity) and slowest (speed)" in slot 1 and work up. – Ƭᴇcʜιᴇ007 Sep 2 '12 at 0:24

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.