The Problem Solving Guy – 1

Based on Guy Serle’s generous, well-informed responses to John “Nemo” Nemerovski’s blog entitled “February is COMPUTER FRUSTRATION MONTH,” the duo teamed up for this first in an ongoing, unpredictable series of troubleshooting features. We welcome your suggestions for future subjects, plus any comments, wisecracks, and flames on or off the topic under consideration.

Guy and Nemo

NEMO: Hey, Guy, I’m confused about RAM for the newest series of Apple desktop, laptop, and tower computers, both G5 and G4. I know that the G5 towers need to have memory installed in matched pairs, but I’m not
really sure why. Can you please explain?

GUY: The answer to your question about matched pairs of RAM in G5 Towers is simple. There are so few Macs in relation to PCs that memory gets lonely and needs a pal to hang with. After all, one is the loneliest number that you ever knew. The G4s were a lot less picky about what type of memory you could plug in (those sluts).

OK, real answer. Because the G5 tower architecture is designed for memory to be added that way. Yeah I know that’s kind of a cop out answer. If you’re not sure what type of memory you need to add to your PM G5, an excellent resource is

They will tell you all you need to know about any (and I mean any) Mac computer you may have lying around. Memory for every model can be cheerfully acquired from one of MyMac’s wonderful sponsors, (unabashed plug).

NEMO: Do new G5 iMacs, with two potential memory slots, also need to have the RAM matched? I asked a salesman at our local Apple store, and he didn’t know.

GUY: The quick answer is no, they don’t need to be matched, but you’ll get better performance if they do. According to Apple, unmatched pairs make the computer operate its memory with a 64 bit data path, while matched pairs will operate with a 128 bit data path. 64 goooood, 128 better. So if you are buying memory for your iMac, you’ll get better performance with two matched 256 MB PC3200 DIMMs than you will with one 256 MB DIMM and one 512 MB DIMM.

The caveat to all this? In order to get that memory matched with the stock 256 MB DIMM that comes with your machine, you’ll probably need to get it filled with memory from Apple when you purchase your machine at Apple’s web store or through an Apple store. Apple’s memory is very expensive as compared to buying it from someone else. If you know your way around the hardware, you can just get the stock memory, examine it after purchase and match it from the appropriate vendor. If you don’t and you want better performance, you’re better off buying it from Apple. You’ll pay a little more, but you won’t have to be bothered about it.

NEMO: What about PowerBooks? Can you place two larger memory chips in them? Again, will it help or be necessary to match their capacities or brands?

GUY: With PowerBooks (of any kind) it isn’t necessary to use matched pairs. You’ll get no performance increase that I know of (beyond the increase from just adding more memory that is). It IS important however to make sure you get the right type of memory for your particular machine.

You can check for your particular machine or try one of the many sites that sell memory. Most of them will list the machines the memory is good for. One site that I know of that’s good for finding the memory you need is Other World Computing. Besides memory, they also have many other upgrade categories. Of course MyMac also has many fine sponsors that will be happy to sell you the appropriate memory as well. Liiiiike, (yes you guessed it)

NEMO: And why does Apple make it so difficult to add a second RAM to iBooks, and make it impossible in the Mac mini?

GUY: I’m sorry, what part of Apple sells their memory for a lot of money did you not understand?

NEMO: Thanks, Guy. Very helpful.

Leave a Reply