Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Notebooks > MacBook and kernel_task

MacBook and kernel_task
Thread Tools
Mac Elite
Join Date: Aug 2001
Location: London, Ontario
Status: Offline
Reply With Quote
Apr 2, 2017, 09:40 PM
 
I recently put a new 240gb SSD in an old white MacBook (2.13ghz, mid-2009). The machine has 4gb of RAM. I am trying to decide whether it is worthwhile to replace one of the SODIMMs to boost the RAM to 6gb. So I started to watch Activity Monitor Memory usage. With, to me, very strange results. On my iMac (27", 8gb, 1TB Fusion, latest model) running 10.11.6 the largest use of memory is always kernel_task at about 800mb. I know this is average. However, on the MacBook, also running 10.11.6, and the same software and files open, kernel_task never appears at all. Doesn't appear in CPU use either. El Capitan runs very well on the MacBook. What I'm wondering is whether, if I put the extra 2gb in, if 10.11 will automatically take nearly 1gb of that (for something like indexing). If so, it is basically a waste of money. I also do not understand why the iMac kernel_task wants that much RAM when the MacBook wants none. Does the Fusion drive system autmatically use that much RAM?
     
Administrator
Join Date: Jun 2000
Location: California
Status: Offline
Reply With Quote
Apr 3, 2017, 03:54 AM
 
kernel_task is most definitely running on all Macs running macOS. Your view prefs differ between the models.

Activity Monitor -> (menubar) View:

iMac 24: View -> All Processes
MacBook: View -> My Processes

Set your MacBook to show all processes, and kernel_task will appear.

Rather than watching how much RAM each process is using, I'd use the Memory tab to watch for pageouts.
     
WizOSX  (op)
Mac Elite
Join Date: Aug 2001
Location: London, Ontario
Status: Offline
Reply With Quote
Apr 3, 2017, 02:04 PM
 
Thanks, Reader50. Yes, that was it. kernel_task uses 345mb of RAM on the MacBook. I'm not sure why it uses less than half as much though. Two possibilitles: the higher screen resolution (although dedicated graphics/2gb should not need RAM) or perhaps with a Fusion drive 10.11 tries to avoid using it for caching, especially when you have free RAM but with a SSD it uses the SSD more when caching?
     
Clinically Insane
Join Date: Nov 1999
Location: 888500128, C3, 2nd soft.
Status: Online
Reply With Quote
Apr 4, 2017, 02:34 AM
 
Is it paging out at all?

As far as using more RAM: unused RAM is by definition wasted. The OS tries to use as much RAM as it can to speed up the system.
     
WizOSX  (op)
Mac Elite
Join Date: Aug 2001
Location: London, Ontario
Status: Offline
Reply With Quote
Apr 4, 2017, 09:15 AM
 
No, not paging out at all yet. I've thrown at it most of what I use. Open Word, Excel, Powerpoint with a few files open in each, with a 30gb movie running in VLC and a few other graphics/web design programs open. The most it ever uses is about 3-3.2 gb of RAM. Would the extra RAM further speed up boot time?
     
P
Moderator
Join Date: Apr 2000
Location: Gothenburg, Sweden
Status: Offline
Reply With Quote
Apr 4, 2017, 10:39 AM
 
Originally Posted by WizOSX View Post
Would the extra RAM further speed up boot time?
No. Faster SSDs speed up boot time, but more RAM (once you have enough to not page out) makes no difference.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
   
Thread Tools
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On
Top
Privacy Policy
All times are GMT -4. The time now is 01:55 AM.
All contents of these forums © 1995-2015 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2015, Jelsoft Enterprises Ltd., Content Relevant URLs by vBSEO 3.3.2