Booting does not clear RAM

When your Mac restarts, it begins with essentially all of the RAM free. The EFI boot firmware uses some, OS X uses some, and all the applications and processes that start automatically use some. By the time you look at Activity Monitor, lots of memory is used.

What version of OS are you running? Modern applications running on the latest OS keep running across an OS restart. (Actually the OS stops them as it shuts down, and restarts them automatically when it restarts.) Just because an application doesn't have any visible windows does NOT mean it's not running and using memory.

Activity Monitor should show you the application(s) that are using lots of memory. Are you sure you don't have some kind of filter enabled that hides some of the processes?

"Cleaning caches" is a vague and usually useless maintenance activity. Exactly what did you do that you thought made more memory available?

Restoring your system from backup won't help (unless your backup doesn't have much software installed, so nothing much will run when you restart the computer.)

I don't get why you have to boot to safe mode. What happens when you boot normally?

Mac09 said:

My Mac has started freezing and Activity Monitor shows that most of the RAM is "wired" (5.3 GB out of 8 GB). There are no CPU processes listed that are using that much memory.

As of now I can only boot in safe mode, and unfortunately, booting is not clearing the RAM. After safe boot, Activity Monitor always shows that 5.3 GB of memory is still wired.

Up until yesterday cleaning the caches seemed to allow a normal restart with cleared RAM, but now that doesn't work. I've downloaded and run a couple of "memory cleaner" apps but they don't help either. I probably need to do a clean restore of my Mac to get it back to normal, but would like to update my backups before doing so. However to do that, I will need to clear the RAM so that I can restart the Mac normally.

Am I going to have to do the best I can in safe mode, or does anyone know of a way that I can force the RAM to clear?

Thanks

Click to expand...

Hi Mac09,

Generally if you've had issues with RAM usage, resetting the PRAM & SMC can occasionally aid how OS X addresses RAM. May I ask if you've tried that?

Mac09 said:

If I try to boot normally, the Mac just hangs after the Apple logo goes away, and the gray screen fills up with strange patterns. I have to just turn it off at that point.

Click to expand...

That sounds like more than a RAM use problem. It could be hardware. In any case, I'd let Apple look at it if you're near a store.

Actually some caches are good for the system to continue to perform optimally and cleaning them may cause more unwanted recourse then a necessary solution.

I would try removing a few ram modules and operate on the bare minimum and see what happens there, reinstall the older modules and try again.

if nothing else, do a clean install and reinstall your applications.

Something wrong with that kext would seem to indicate a strange software bug or a hardware problem with the GPU. As there are few, if any, reports of similar problems you may have a hardware problem.

Surprised no one mentioned the free and awesome memtest utility.

It sounds like you're all set now anyways.