Please Help with RAM Speed / RAM Installation Question

[jtbrown]

The short version: My early 2009 iMac (model 9,1) came with 1066 MHz memory cards; should it work with 1333 MHz memory cards? (It doesn't, but should it?) Also, if my iMac is unable to start with both 1333 MHz memory cards installed, is there any way I can test them to see whether they are defective?

The longer version: In order to upgrade from 4GB to 8GB of RAM, I recently ordered two RAM cards from Mac RAM Direct for my early 2009 iMac (model 9,1). (This model has two slots for memory cards; it came with two 2GB cards, and I ordered two 4GB cards to replace them.) Instead of the cards I ordered, which the guide on their own website directed me to, they sent me different cards; the most salient difference is that the ones I ordered were 1066 MHz (like the ones that came with my iMac), while the ones they sent were 1333 MHz. The 1333 MHz cards appear to be the ones that Mac RAM Direct recommends for 2010 iMacs.

When I e-mailed them to ask how to go about exchanging the cards I ordered for the ones they sent, the reply I got was
"Tech says the 1333 parts are the upgrade for the 1066 machines. Please just pop them in and you should be good to go." I popped them in and I was not good to go; when I tried to start the computer, I got three beeps, repeated at intervals. To make sure I hadn't installed the cards incorrectly, I swapped them for the original memory cards, and the computer started normally. I then switched back and forth two more times, and each time it started with the old cards, but not with the new ones. Thus, I'm quite sure that I'm getting the cards in all the way, etc. (I mention this because I've read that not pushing them in far enough is a common novice's error.)

Obviously these particular cards do not work in my computer; I suppose there's a chance that they're simply defective (or perhaps that one of them is?), but I strongly suspect that the speed is the problem, and/or that there are other differences that make them incompatible with my machine. However, I don't know for sure -- does anyone out there? And given that my computer won't start with the two 1333 MHz cards installed, is there any way I can test them to see if they're defective? (For example, can I install just one card at a time and try to start the computer, in case one card is defective? Can I install one of the 1333 MHz cards and one of my old 1066 cards?) I'm concerned that Mac RAM Direct will try to charge me a restocking fee if I return cards that aren't actually defective, even though the cards don't work in my computer and aren't the ones I ordered.

Thanks in advance for any help you can give me, and sorry for the long post.

Todd Brown

 

[BigBeast]

The speed should not be an issue. I'm not sure if that model SUPPORTS 1333 RAM but you can put faster RAM (1333) into slots that are slower (1066). iMac RAM needs to be 204 pin DDR3 So-Dimm- so make sure that's correct.

Try turning your iMac on using only one module at a time. It's possible one RAM stick is dead.

Try running the Apple Hardware Test that comes with your system restore discs to test the RAM.

 

[jtbrown]

Thanks so much for your prompt reply. The label on the memory cards indicates that they are DDR3 SO-DIMM, but says nothing about the number of pins. I'm assuming that the cards have 204 pins because they fit into the slots; is that a valid assumption? Also, when I try to start it with one card installed, does it matter what slot I put the card in? I'm guessing it doesn't, but thought I should ask just in case. Finally, if the speed really isn't an issue, are there any other specs I should check besides making sure the cards are 204-pin DDR3 SO-DIMM?

Thanks,
Todd

 

[BigBeast]

Thanks so much for your prompt reply. The label on the memory cards indicates that they are DDR3 SO-DIMM, but says nothing about the number of pins. I'm assuming that they are 204 pins because they fit into the slot; is that a valid assumption? Also, when I try to start it with one card installed, does it matter what slot I put the card in? I'm guessing it doesn't, but thought I should ask just in case.

Todd

Your assumption is fine. You can also try visually matching up the pins from your Apple memory to the new memory- just to make sure everything looks right and lines up correctly.

I don't think it matters what slot you put it in- but you could try both slots separately (if one doesn't work when you put it in)... Sorry I don't have any better information for you than "experiment."

 

[jtbrown]

OK, I tried them one at a time, and the computer didn't start up with the first one, but it did with the second. It seems to be running fine with that one -- it shows up in the "Memory" section under "About This Mac," and is listed as 1333 MHz. (Though I don't know whether or not that means it's actually running at that speed.) I also ran the Mac Hardware Test, and it found no problems.

Meanwhile, however, I've heard back from Mac RAM Direct. Now the guy says that my initial assumption was correct and (as he puts it) "the 2009 models don't like the faster modules"! When I wrote back to tell him I had gotten my computer to start up with one of the 1333 cards, he elaborated slightly, writing, "There is a bit of a processor, system and firmware range in the iMacs from 2009 to 2010 and some are fussier than others. Yours is earlier and the 1066 is best." I'm not sure what that really means, but the upshot is that they're going to send me the cards I ordered in the first place.

Even so, I really appreciate your advice, BigBeast, and I suspect that it was sound (i.e., that the 1333's would work if not for the fact that one of them is evidently defective). Thanks very much for taking the time to answer my questions.

Todd