Mac RAM?

[WorldIndustries]

If I wanted to upgrade the RAM of a G3 iMac, would I need a specific brand of RAM, or more specifically, RAM made for a Mac? Or can I use any brand (ie; Kingston, from an old PC)? Actually, do the iMac's even use SDRAM? Or do they use SODIMM?

 

[The General]

Pretty sure it's just regular PC133 SDRAM (not DDR) but you can check here to make sure.

 

[King X13]

also a G3 can only support like 384 megs of ram if im correct. so dont buy to much.

 

[mac_mogul]

My iMac G3 holds up to 1gb of PC166 SDRAM.
Older iMacs (tray loading cd) only hold 512mb PC66 SDRAM (if i'm not mistaken)

And RAM is RAM. There's no specific Mac ram or PC ram.

 

[macdude425]

...however, long years ago, they did use "standard" RAM, but wouldn't buffer it or would use different voltages, requiring you to buy special RAM. However, it has not been this way since at LEAST late 1997.

 

[CanadaRAM]

OK, lets go back to the basics.

First of all, there are two series of iMac G3's

The Rev A - D machines have a tray-loading CD drive, and have speeds from 233 MHz to 266 Mhz to 333 MHz (always ending in a 3 or a 6).
These machines take PC66 SODIMMs and will not take high density modern SODIMMs. They can go to a maximum of 512 Mb with 2 x 256 Mb SODIMMs -- Except -- that some of them have motherboard bugs that limit them to 384 Mb (128 + 256) RAM. There's no way to tell in advance whether it will take 384 or 512, other than the higher speed units are more likely to work.

The iMac G3's with slot-loading CDs and speeds from 300 MHz to 700 MHz ending in 0, all take PC100 DIMMs. PC133 DIMMs will work too if they are low density. These machines can go to a maximum of 1 Gb with 2 x 512 Mb DIMMs.

In general, although "PC Generic" RAM may work if it meets the specification, the Apple machines are picky about the Serial Presence Detect settings of the RAM. If the SPD is programmed wrongly, the Mac may reject the memory. So it is safest to buy from a reputable seller who tests and guarantees compatibility with Mac.

Thanks,
Trevor
CanadaRAM.com