If this is getting to look like a disk failure, it is important to backup your system onto an external disk as a matter of priority. I suggest using Carbon Copy Cloner (CCC). If the cloning process throws up any error messages about bad sectors, it is a sure sign the computer disk is on the way out.
You should download a fresh installer and copy it to the clone, as you can do more thorough testing from outside the system. But your own data and media is the most important thing..
Unfortunately, Mountain Lion has bugs. We had a problem with ML coming to a complete crawl when we did a 10.8.3 upgrade. After looking at the log files we traced it to a KEXT file (kernel extension) from a third party vendor. We got rid of that and the system worked fine...but it was working fine with 10.8.2.
The link below is a link for troubleshooting system performance problems in ML:
Using Activity Monitor to monitor the system might show you something's wrong, like a process or application suddenly becoming a memory hog, but I'm inclined to agree with Linc Davis that something is likely wrong with the system. Years ago I had a Mac Mini that had an erratic problem like that and I had to take it back to the Apple store 3 times before they were able to catch it. You might also want to pay attention to which apps you've got running and see if one of them is causing the problem.
Hope this helps, and good luck.
Unfortunately, Mountain Lion has bugs. We had a problem with ML coming to a complete crawl when we did a 10.8.3 upgrade. After looking at the log files we traced it to a KEXT file (kernel extension) from a third party vendor.
Which is it? ML Bugs or third-party crapware? I'm not sure how the latter implies the former.
10.8.3 was seeded to developers for a long time; certainly plenty of time for the kext developer to fix the issue prior to its public release.
Well, Barney, in this case I guess you'd call it "third party crapware." I don't think the vendor has a bad reputation and it's not the company that I used in the link above.
With that said, however, here are the problems I've experienced with Mountain Lion:
- TextEdit has crashed several times for no reason (and no, it's not the "File: <3 slashes>" bug)
- iPhoto sometimes fails to recognize a camera with pictures is connected to the system
- iPhoto periodically erratically crashes.
- iWeb crashes
- Safari Web Content has gone wild erratically eating and freeing memory (I observered that using the info in the link I've provided above)
- Full indexing using Spotlight seems to occur at the drop of a hat.
- The new "Notes" app can't run anymore than about 3 minutes without crashing
I don't think the above fit neatly into your label of "third party crapware" since everything I've listed is an Apple product. I liked ML, but switched back to Lion because it got to a point where I felt ML couldn't be trusted.
The problems with Mountain Lion seems to be that it's finicky about hardware, and that's nothing more than an educated guess. Some people seem to swear by it, others seem to swear at it. Do the following Google search:
"Mountain Lion Bugs"
and you'll see what I mean.
I cloned my ML volume to a FireWire drive because I assume these will be fixed in time. When they are I'll likely put ML back on, but not until then.
I have a seagate hybrid drive in my macbook (500 gigs) and it relocates applications on the the 4 gigabyte flash drive as part of the hybrid drive. It does this under hood. Could relocating Safari onto the flash drive cause it to crash more often? I know that Safari needs to be in the applications folder to be stable. I also at some time in the past installed webkit Safari browser onto a RAMdrive but that would crash allot so I got rid of it. Maybe what I did with webkit broke Safari?