I need help


macrumors 604
Original poster
Jul 4, 2001
1 Block away from NYC.
I'm trying to upgrade memory for my imac. And I have 96 Mb of Ram. I have a built in 32 mb and 64 of scond slor Ram. I want to max out the memory. Can I move the 64 Mb of Ram down to replace the 32 MB of Ram? And then I want to know how much I can put in the Expansion slot.
I have Two Places witch Say different things.
Alpha memory says
Standard Memory: 32MB (removable)
Maximum Memory: 384MB
Memory Expansion: 2 Sockets
And Crucial Says
Manufacturer  Apple
Model  iMAC (G3-233, 266, or 333)
Maximum Memory  256MB
Standard Memory  32MB removable
Number of Slots  2 (2 banks of 1)
Notes  To access the second slot requires the removal of the microprocessor board which should only be performed by authorized Apple service technicians.


macrumors 65816
Jun 18, 2001
WestCost, USA
This is what I know

I read some place that you can stuff more than 256 in an older iMac. But the RAM does not run as fast as it is suppose to. I dont know why.... but it makes sense if you think about it. What iMac do you have? I have an Rev-A original. As for moving your 64MB stick to the lower level. It well only work if it is a "slim" stick ment for the bottom slot. They make ones that are thinner for the bottom so it well fit right. I have never tried to stick a normal fat one in the lower slot. Why dont you just get a slim one for the bottom slot and keep the 64 on top... or better yet.. just get 2 new sticks :) When I got ram for mine... I trashed my 32MB chip and got a slim 128 for the bottom. They are the same price as the fat ones. They should be cheep by now.


macrumors 65816
Jun 18, 2001
WestCost, USA
You should get a MaxPower

Nice a Rev-A :) I love mine. Its done a lot of service. I have never had problems with it. Its a little old now and I am going to retire it. Soon. It looks like its going to become a FTP server and a fire wall for my network, as soon as my G4 gets here. Well see if it can handle it. I got a 466 G3 upgrade for it made my newerTechnologies. You should look into it. Newer when out of bussness a while ago so I dont know if you can find one out there.. but i bet they are cheep. I know that they were selling them for nothing when they went under. It gave new life to my iMac.


macrumors 6502a
Jun 7, 2001
Sure you can

Ive switched the top and bottom ram and never had a problem. Ive even took some of the ram from my iMac and put it in my pismo. I dont know why the top and bottom ram slots are sold as being two different things, in my opion they're the same thing. How about upgrading the harddrive in it.


macrumors 68030
Aug 1, 2001
Santa Cruz Ca

The 256 offers are usually a pair of 128's. The Low Profile DIMMs for the lower slot are 1 row instead of 2. The Pismo RAM is similar enough for the above swap but not recommended both ways as the width of some Pismo modules are just microns too wide for the rev A-D models.
I want to know if a Pizmo 500 processor card would fit successfully in my revD 366 Imac.I also want to know if I can tie together rev A motherboards by their mezzanine slots to parallel process under X or X server.
I have a clean Predator case I'd like to stuff full of Apple hardware for a cookin' VFX machine.


macrumors member
Aug 12, 2001
1) RAM
The Rev A iMac supports up to 512mb of physical RAM.
The top RAM slot supports High Profile DIMMs only and the bottom slot supports high and low profile.

2) The Mezzanie slot can be fitted with a specially designed Voodoo2 card that was made available by a company that I believe is now out of business. If you search around though, you might be able to find one.
I believe Formac offered some sort of SCSI/ProTV combo that fit in the slot, but no longer offers it and I cannot find any record of it. So I might be wrong on that.

Low & High Profile RAM
Not the cheapest, but at least assured to be the right fit.


macrumors regular
Sep 21, 2001
The Moon

JoyBoy, I don't think that that's true about the Rev A iMac I don't think they CAN support up to 512MB because I tried to up grade my iMac to have 256x2 and the Apple Technitions told me that that wasn't possible. I had to settle for 128x2.
Then again maybe mine iMacs just fudged.


macrumors newbie
Jul 24, 2001
A quick google search


returned an article on the Mac Observer that states the revision A-D iMacs, WallStreets and Lombards can take 256 meg dimms.


That's news to me! I'm going to grab a couple of 256 meg dimms and see how it goes in my stepmom's iMac. My advice is to upgrade to at least 384 megs - I'd personally take the plunge and go for 512. If you're serious about upgrading the computer, why not top it out now. You'll probably extend the usable life of the machine by doing so and the cost difference is low. You will also be much happier running OS X with 512 megs versus 384 or 256 megs.

There is the V2 graphics card, but I'd avoid it because I hvae heard that slot is disabled by a firmware update. You'd probably get more bang for your buck by getting RAM and a CPU upgrade.

3DFX card:


I'd upgrade the hard drive at some point in time, since today's IDE hard drives have improved much since the iMac days. I know that I'm getting ready to yank the Fireball 6 gig that my stepmom's iMac came with and replace it with a Maxtor or IBM, whichever is quieter. Just remember, though, if you upgrade to a hard drive larger than 8 gigabytes, partition the disk so you have at least one partition within the first 8 gigs of the drive. A bug in the firmware on many machines prevents booting if the startup file is beyond the 8 gig point on the drive. If you have multiple partitions, make sure that any and all partitions you want to be bootable reside within the first 8 gigs of the drive.

Finally, there are two other upgrades that would be worth it, and they are also compatible with future versions of the Mac OS:



Upgrading the CPU is probably the ultimate deal for the iMac, but if it were me, I'd go for the RAM first, since the CPU upgrade might become less expensive in the future.

Good luck!


macrumors regular
Jul 27, 2001
10 Minutes from Disneyland
i have an iMac 233 with 512 MB of RAM

no the mezzanine slots can not be connected

the VooDoo card is still easily found

The SCSI Card doesn't work richt (i went through 3 of them, 2 installed by Apple)

Processor upgrades kick but....

and the iMac itself doens't usualy recognize the 512 (256x2) unless i'm in OS X, in 9.2 it sees 256....

anything else?
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