I recently bought a couple of memory modules from Kingston to be used on my MacBookPro 13" 7.1, they are KVR1333D3S9/4G which should work fine with the computer as the frequency and latency is supported, but when I installed them OSX will never boot, it stops on DSMOS as arrived.

The only way I fount to make it work is using one of the KVR and one os those that the computer originally had. But then the memory works at 1067 and worse,I don't have 8GB but only 6.

Googling I found that I should had to buy a certified memory, and I know, I should googled a bit more before buying this memory, but I don't want to give up, not now.

Does any of you have a "trick" for this kind of memory to work.

  • I forgot to mention that using safe mode both modules work, but I don't want to keep the computer in safe mode all the time.
    – markuz
    Commented Feb 25, 2011 at 1:48

3 Answers 3


There really isn't any trick for running RAM that your Mac doesn't like. It appears that Mac OS X is more forgiving of RAM problems in Safe Mode (which makes sense, when you think about it).

But it sounds as though one or both of the Kingston memory modules is bad. I suggest that you install one of the modules, then boot normally and run Memtest, then swap that module for the other one, and run Memtest again.

You can get Memtest for free at this link:


If one module is bad, then exchange it. If both modules test OK, then you are still best off returning them to where you bought them for an exchange.

  • I've tried both modules separatedly and they work fine, I used also a Linux live CD to test the memory and work as usual (with no changes to the HDD) and it seems the memory are working nice. I believe the problem is with DSMOS. :-(
    – markuz
    Commented Feb 28, 2011 at 20:21

The problem is that the 7,1 chipset supports 1333mHz, but the onboard video crashes. Here is my answer to a similar question. Basicly you should do one of the following:

  • Combine 1333 & 1066 MHz DIMMs (and system will run fine on 1066MHz)
  • Flash the DIMMs SPD (to make it report 1066 MHz speed). (I did that successfully).
  • Buy new 1066MHz DIMMs

I've the same problem. Identical modules reference. I think that Kingston needs more power to run properly, so now I'm going to try with another type of memory like Corsair.

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