Yesterday my Mac Pro 1,1 (2007) running 10.7 started freezing up. It keeps on doing this after restart. Usually it will perform one task, but when asked to do a second, it freezes. The cursor will still move but I can only do a hard reboot to get out of the situation.

It is independent of which software I start up.

I have installed a SSD drive for the System OS; upgraded memory to 14 Gb installed a new graphics card.

DiskWarrior 4.3 will not deal with my drives because my OS is too new (although 4.3 should be compatible with Lion) but it did do a diagnosis of the drives and found nothing wrong with them (it did report a few files with problems). Disk Utility also tested the drives and found no problems.

Should I test the memory? The added memory is about 5 weeks old, though (2x4Gb Kingston). Or could this still be a SSD failure?

  • Yes, the memory is usually the first indication of a freeze. I just had a macpro(1,1) memory issue, could be coincidence, or could be a pattern.
    – jnovack
    Apr 5, 2013 at 14:48
  • As the very first thing run the Apple HArdware Test to ensure that your memory is ok, then suspect the SSD. Apr 16, 2013 at 9:23

5 Answers 5


That could be a lot of things. It could be the system, it could be the hard drive, it could be a drive cable...it could be lots of things. It sounds like it's a drive problem.

The following links are "how-to" links from the guys that make Scannerz. One is how to use activity monitor to try and isolate processes that are using too much CPU/Memory etc and the other is about bad hard drives. The Activity Monitor post says it's about Mountain Lion, and clearly some of the topics are Mountain Lion specific, but in general it shows how to use Activity Monitor and some tricks I never new about. Here are the links:



Although you have an SSD, I was surprised to see a post on MacRumors where someone used Scannerz on a system that was having problems that sounded similar to yours. Scannerz found bad cells in the SSD. The owner is replacing the SSD under warranty. He also found his cable was bad. Talk about bad luck!

If I had a link to it, I'd post it but I don't. You could go to MacRumors and search their forums for "Scannerz" and I would think you would find it. Like some of the other posters in that thread, I though SSDs were supposed to automatically correct bad blocks, but apparently that applies only to sectors that have depleted their write ability.

Hope this helps.


That might be a cable problem, or it might be the SSD. The fact that the OS told you that the drive had been removed likely means the supply dropped on it, which can happen if you have a cable making intermittent contact in the supply lines in the cable. In essence, if the supply lines in the SSD cable are making intermittent connections, the moment the they go open, the OS detects it as an improperly ejected drive.

If you're using the same cable with the HD and the problems don't re-appear, it's probably the SSD. If they start happening with the HD, then the cable might be the problem. Like I said in my previous post, SSDs are not as infallible as their manufacturers would have you believe.


I would test the RAM. Try the old RAM. Just get that out of the way.


First I would consider resetting NVRAM and PRAM and SMC.
If crash still happens in my opinion you should stress test your hardware to find what is not working properly. In order I would test:
- Ram (MemTest)
- Video Graphics (run Apple Hardware Test 2-3 times)
- Check SSD life with vendor's utility (also check for a firmware upgrade if ram and video graphics are ok but just if it's your last chance)


I tested all the RAM with memtest, no errors even though the test sometimes hung. At one point OS told me that I had irregularly removed a drive, which I had not, and lo and behold the SSD drive did not mount after restart. Upon installing 10.7 on a new partition of a HDD, and removing the SSD drive, all problems disappeared. I could not run Apple Hardware Test because Safari refused to launch, even after a complete reinstall of the OS. This also pointed to the SSD. Although DiskWarrior and Disk Utility had found no problem with the SSD, it was the culprit.

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