Slow Mac Book Air, high system cpu usage

[milesmeridith]

My mac book air is running slow and I'm not sure why. When I go into activity monitor the RAM looks good, the HD disk space is good, but the CPU usage is high. Particularly system. It gets up to 85% even when I only have one or two programs open that take up less than 10% of the CPU usage. Any suggestions?

[Stanley]

I'd check activity monitor to see what is using the CPU so heavily.

If you click the % column, it will list processes in usage order.

[milesmeridith]

I did sort it by CPU usage and nothing is showing high usage except the one or two applications that are running and they combined are less than 10%. So basically none of the system processes listed show substantial cpu usage.

[pigoo3]

It gets up to 85% even when I only have one or two programs open that take up less than 10% of the CPU usage. Any suggestions?

What two programs are we talking about?

- Nick

[milesmeridith]

What two programs are we talking about?

- Nick

It doesn't matter, but I had Outlook and firefox most recently. I mostly just use my computer for email and internet.

[pigoo3]

It doesn't matter, but I had Outlook and firefox most recently. I mostly just use my computer for email and internet.

Of course it matters...that's why I asked the question. You didn't mention what the two apps. were originally...that's why I asked. If you were using two high-demand apps...that could explain the high cpu usage.

You can be "just using Firefox"...and that can cause high cpu usage. The measure of "high cpu" usage isn't that your "just" using Firefox & Outlook...but what you're doing when using those programs.

For example...if you're using Firefox to watch You-Tube videos on the internet...your cpu usage will get very high!!! This is just one example...there are many other possibilities as well.

- Nick

[Stanley]

if you're using Firefox to watch You-Tube videos on the internet...your cpu usage will get very high!!! This is just one example...there are many other possibilities as well.- Nick

Due to Flash usage?

If so, that can be massively reduced by viewing the files as H.264/HTML5, etc.

[pigoo3]

Due to Flash usage?

If so, that can be massively reduced by viewing the files as H264, etc.

As I mentioned...watching You-Tube videos is just one example...and the older the computer...generally the higher the cpu usage.

Various results for flash player watching the same video (cpu usage):

- 2009 Mac Pro - 35%
- 2008 MacBook Pro - 60%
- 2007 MacBook Pro - 70%

I'm sure amount of ram & type of gpu play a factor. Also...full screen vs. small window...HD video vs. non-HD.

There are other things that can also cause high-cpu usage on the internet as well. Watching You-Tube videos is just one.

- Nick

[milesmeridith]

I didn't mean to imply what you asked didn't matter I meant, the high system cpu usage happens no matter what applications I have open. So it could be firefox and outlook, or it could be just excel. The slowness doesn't seem app related. And if Firefox was the problem wouldn't that show up under user % instead of system?

[vansmith]

Next time you see this happening, go to File > Save and save a copy of your process list. Once you've done that, post it here and we'll take a look.

[pigoo3]

I didn't mean to imply what you asked didn't matter I meant, the high system cpu usage happens no matter what applications I have open.

Ok...I see...the "It doesn't matter" statement was a bit confusing!

So it could be firefox and outlook, or it could be just excel. The slowness doesn't seem app related. And if Firefox was the problem wouldn't that show up under user % instead of system?

Of the applications mentioned...I would say Firefox (or any internet browser could be the culprit). With the internet browsers...what you're doing on the internet can make a big difference.

For example...if you're on Mac-Forums...cpu use will be low...but do things like:

- view You-Tube videos
- play online games
- do video chatting
- etc.

Now I know...you're probably going to say you don't do those things. What I am saying is...from time to time you're visiting certain web pages (or some sort of internet based task) that will increase cpu usage.

It may also be interesting to know (at least in my experience)...that sometimes the " high cpu values" in Activity Monitor will remain high even AFTER you stop doing whatever it was that spiked cpu use. And that could be from a couple days ago.

My advice is. When you see high cpu values...and you don't think you're doing anything "heavy-duty"...restart/reboot the computer. The will "reset" anything that's "out of wack". Then you can start fresh.

- Nick

p.s. Your computers age & system configuration (ram, cpu speed, video hardware, etc.) can make a difference as well.

[pigoo3]

Next time you see this happening, go to File > Save and save a copy of your process list. Once you've done that, post it here and we'll take a look.

A very good suggestion!

- Nick

[milesmeridith]

As you can see the system CPU usage is almost at 80% but there is nothing indicating what is utilizing the 80% in the processes.

[pigoo3]

As you can see the system CPU usage is almost at 80% but there is nothing indicating what is utilizing the 80% in the processes.

Kind of hard to "see"...the image is on the small side. I did zoom-in to max....but the whole Activity/Process list can't be seen. Need to scroll down to see the rest of the list...and post that image.

- Nick

[vansmith]

In the box that says "My Processes", change that to "System Processes."