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macrumors member
Original poster
Jan 27, 2013

I have a mid 2013 MBA with 8gb ram.
And for some reason it runs out of ram and the MBA becomes unusable.
When the problem occurred only 2 programs were running:
safari (for netflix)
opera (for facebook)

After a hard reboot the problem stops for like an hour.

Does someone know what the problem might be and how I can fix it?

Kind regards



macrumors 68020
Apr 23, 2010
Use Activity Monitor to see how resources are being used. You may need to read up a little bit on how to interpret, but mainly you want to see if your using any swap.
Safari, like other web browsers, can view web pages that consume memory like a black hole. This is not unique to Safari, and imho Fox is way worse. But, if you quit/restart Safari, does memory consumption (with he same tabs) go down? I think you said it does with a system restart...


macrumors 68020
Jan 23, 2017
kernel_task (4 to 5gb) and safari-webmaterials (1,5 to 2,2 gb)

That kernel_task figure is insanely high (unless components of Safari are counted as core OS functions?) Even with about 150+ tabs open while running like 15 browser extensions with 30+ videos that have been allowed to load, the OS itself is not using much memory.

Screen Shot 2017-06-26 at 11.01.36 PM.png

In my opinion, you may want to try booting the system into Safe Mode and resetting the PRAM/SMC. You could also check your launchd folders to see if any Apps are loading at startup/login that you do not recognize or want to load. If that does not work, you could try using Onyx Automation to dump the System and User cache, execute scripts, rebuild the Spotlight index (Sierra has a flaw with this so be sure it actually rebuilds the index as, if it does not, you may need to use Terminal to do so.) If that has no effect, running Apple Diagnostics/Apple Hardware Test and reinstalling OS X might not be a bad idea.
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macrumors 601
Mar 4, 2005
.. London ..
I have the same 2013 MBA with 8GB RAM. It's a lovely machine and has enough RAM to handle almost anything. I tried running every app at the same time and it still ran fine. The only thing that might cause problems would be if you were running more than 2 or 3 fully loaded virtual machines at the same time, e.g. OSX + Windows 10 + Linux + Windows Server + Windows 8 all at the same time. That's not something many people ever do.

OP, when you say hard reboot, do you mean holding down the power button to force a reboot without a graceful shutdown? In that case, kernel might be doing a full rebuild of various databases / caches / traversing the SSD, rebuilding mailboxes and so on due to data corruption caused by the multiple hard reboots. In that case, best to leave it to do its thing, which will take a few hours to get everything back on an even kneel.

Next time try to do graceful shutdowns by shutting down via the Apple menu.


macrumors 68000
Apr 3, 2012
If possible, I would suggest to OP to backup and reinstall from fresh the OS. It took sometime for sure, but chance it solves your issue (and also other potential issues) is pretty promising.


macrumors 6502a
Apr 3, 2010
Central CA
Yes, it is a "runaway" process, but I wouldn't get too excited unless it persists over time.

Just reboot, and open up Activity Monitor, and check it out periodically. I've noticed kernel_task going out of control when I plug in an external drive and it wants to index it for Spotlight, or if I import a new Photos library, and it wants to scan it for new faces...sometimes it works on something and needs large amounts of memory, for a while, and your best option is just to let it do its job and finish.

If anything is a memory hog, IMO, it is always seems to balloon up until it gobbles up all the available memory it can grab. I periodically quit it, and then open it up again.
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