Correct SDRAM, and what is the ram ceiling in a Dual 1Ghz Quicksilver?

Question

Hello all,
Thanks for helping me with my optical drive question earlier. I now would like to ask about ram. At present my G4 1GHz is running OSX Tiger on 256Mb ram. Things run ok, but they could definitely be better.
My G4 is one of the older Quicksilver models and uses SDRAM as opposed to DDR. Specifically it requires:
SDRAM, PC133 • CL=3 • Unbuffered • Non-parity • 133MHz
At first I thought I could simply transfer the larger ram sticks from my old G4 400MHz sawtooth, but the Quicksilver is very picky and doesn’t like any of them. I thought it would be backwards compatible and just slow everything down to the slowest speed memory stick (PC100 in this case), but no... it just didn’t like them full stop! (on a side note, I’ve checked and all 3 memory slots on the Quicksilver work fine, nothing defective there).
Once again working on a shoestring I would like to ram up that memory to 1Gb or 1.5Gb as I have a disc for Leopard and I would like to upgrade to that sometime soon.
So, looking on eBuyer I can see what’s described as ‘Generic’ 512MB PC133 168pin Extra Value SDRAM for £11.99 which I see as great value (here's the link). The only thing I cannot tell is if its the CL=3 variety. This means two questions:
1) Is 1.5Gb the max ram limit for a January 2002 G4 Dual 1Ghz Quicksilver, or is that simply Apple’s ram ceiling at the time? Have people put in say, 2.5Gb on these machines?
2) Is ‘generic’ ram a complete no-no for these machines? I really can’t see why not, but I’m not that knowledgeable either.
Many thanks for your help.
Message was edited by: One Brain Cell

Answer 1

The QS didn't like PC100 because it has a 133mhz system bus. You can use PC133 in a machine with a 100mhz bus, but not conversely.
The max RAM is still three 512MB modules for a total of 1.5GB. That model isn;t one that can exceed the original specs.
2) Is ‘generic’ ram a complete no-no for these machines?
Unless identified as suitable for Mac, most of the generic stuff turns out to be for PC. The site you linked does not provide enough support info, and Googling the "manufacturer's part number" doesn't lead to a manufacturer site, just a bunch of circular references back to the seller's site. Suspicious
You should probably call the seller and ask for someone who knows Mac RAM. In addition to being unbuffered and non-parity, it needs to be low-density.
With such a paucity of key Mac metrics, that listing makes be very nervous. I know RAm is expensive in teh UK based on a lot of psots all over Apple Discussions, but you have to find someone who knows Mac RAM.
There is a great free tool for checking whether any Mac can handle more RAM than the original specs showed. It's the MacTracker database and is here:
http://www.mactracker.ca
I couldn't work these forums without it. It shows all the facts and specs of the machine, and always indicates if the original RAM specs can be exceed. For example, for the USB 2.0 eMacs, its Memory entry is:
2.0 GB (Actual) 1.0 GB (Apple)
Very handy.