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waffffffle · Nov 12, 2003, 07:38 PM

I have a G4 400 that I purchased for an academic project. This is my first PowerMac and I have never owned a PC so I have a dumb question about RAM. Can I just buy any PC100 memory module for it and it will work? Do I need to be sure of anything else? It seems that generic PC100 RAM is cheaper from some RAM vendors as opposed to their "Power Mac RAM" which I am assuming is the same thing.

tr · Nov 12, 2003, 08:28 PM

yeah, PC100 will work fine, so should PC133. for the record, i've bought generic PC RAM for my G4 450, and i've never had problems.

tr

reader50 · Nov 12, 2003, 10:24 PM

Generic PC100 or PC133 should work. One caution, if you are buying 512 modules, then spend the extra and get Mac-certified RAM. Assuming this is a Sawtooth (AGP) motherboard, the 512 modules are the upper limit that the motherboard can address. And most generic PC RAM uses a different Column/Row layout that what you need. In other words, the generic 512 would likely be not recognized, or appear as a 256 module.

If your G4 is a Yikes (PCI graphics) G4, then 256 MB modules are the max you can take.

The Placid Casual · Nov 14, 2003, 04:38 AM

If it is a 'Mystic' G4 400 machine, doesn't it need PC133 unless you want the bus to downclock to 100Mhz?

The Placid Casual · Nov 14, 2003, 04:40 AM

My Bad, please ignore my previous comment...

CIA · Nov 14, 2003, 07:45 PM

Usually PC133 and PC100 are nearly identical in price.... I'd get the 133 just in case you ever need to migrate to another used Mac.
Also, make sure you buy low density memory. I bought a gig of PC133 (4 sticks) for $166. Look on Pricewatch

bradoesch · Nov 15, 2003, 06:04 AM

Originally posted by CIA:
Usually PC133 and PC100 are nearly identical in price.... I'd get the 133 just in case you ever need to migrate to another used Mac.

Was just going to say the same thing. You might even have trouble finding PC100 RAM these days, since PC133 is backwards compatible with PC100 and PC66, so why would stores carry all three?

waffffffle · Nov 15, 2003, 06:42 PM

Thanks. I bought a 256MB PC100 module from 18004memory.com and I installed it today but the Mac refuses to boot with that RAM installed. It currently has a 128MB module only and will only boot if that module is installed alone. If I install both or just the 256MB module it won't boot. Does anyone know why? Is this definitely bad RAM?

Thanks.

CIA · Nov 16, 2003, 09:12 AM

Dunno, you probably need to return for a new module, or eBay it and buy another. If worse comes to worse, Crucial is known as one of, if not the, best memory dealers out there. You will pay a little more, but it'll work for sure...

waffffffle · Nov 16, 2003, 03:51 PM

The RAM fits in the slot, so I can be sure that I ordered the proper memory, right? This one is definitely a dud?

CIA · Nov 16, 2003, 06:43 PM

There is a chance it could be high density memory... Do you have another mac or a PC handy that you could test it in? Also try the hardware test disk that came with your machine, it has an extensive memory test.

osiris · Nov 18, 2003, 09:26 AM

For the G4 400, stick to PC100 222 ram.

If you start mixing PC133, or PC100 333, 322, you'll have different chips running at different timings, which can cause trouble. I've seen old servers crap out with mixed chips that otherwise work perfectly well on their own.

Keep it all the same if you can and GD it, buy good quality ram from a Mac vendor.