My Macbook was getting hot, and I think I know why.

Question

I have a week 22 build and it usually runs anywhere from 40-53C, but yesterday it was running in the 60-75c. I started to get a little worried that maybe my computer was taking a turn for the worst. I noticed that even when I was running just a few programs it was still using 35-50% cpu usage. I closed everything up except for large a download I had going, but I still had a lot of background apps still running in the activity monitor. (oh I close applications usually by having the program active and using "apple + q".) I figured maybe I should just restart my computer when it rebooted I open safari and continued my download and my cpu% dropped where it should have been 5%-10% and thus the temp dropped.
The only thing I did different with my macbook yesterday was mutli-task a plethora of different applications to really put it to the test, but that had been hours before I rebooted. The computer cpu usage would not correct itself until rebooted.
Any thoughts?
Thanks
EAH22:)

Answer 1

You can edit your post for a while immediately after creating it. But don’t wait too long.
If you look at the Activity Monitor shortly after you restart but before you’ve launched any of your programs, you’ll find that there are lots of processes running. This is normal.
When you are running lots of applications at once it may or may not cause the processor to work harder. If the programs are running but not doing anything then the CPU won’t have to work any harder than if you had only one running. OTOH, lets say you start Photoshop running a filter on a batch of files, then run a search/replace on a huge Word file, then start a download in Fetch, and then begin browsing the internet - yep, the computer is going to be quite busy. As the jobs finish, or as you quit the programs, CPU usage will drop.
Your computer was getting warm, but that’s what a computer does when it is being used. I’ve had CPU usage top 90% for quite a long time and the temperature topped 85c. The fans came on and once the CPU usage dropped the temperature also slowly dropped. That’s normal.
Why didn’t the CPU usage drop when you quit everything but Safari? Perhaps Safari was the program hogging the CPU. It does sometimes. Did you look at the Activity Monitor and identify which processes were using lots of cycles? When you are looking at the process list you can click at the top to change how they are sorted. Sort by CPU usage.