If you use a laptop, and your battery dies quickly, check and see if you accidentally left iTunes open on an iTunes Store page, even in the background. Look how much CPU it uses to simply display a front page, and rotate graphics in the carrousel at the top of the page (the display is from iStat Menus):
Lest you think that a lot of the CPU that iTunes is using is to play that Allman Brothers song, here’s what happens if I switch out of the iTunes Store.
Together, iTunes and coreaudiod, which processes audio played by iTunes or other apps, use about 7% of CPU.
So don’t leave iTunes open on an iTunes Store page in the background if you’re using a laptop.
Between this and your Time Machine saga of things unnecessarily chewing up battery life, it’s worth remembering that this isn’t *purely* an issue that only pertains to battery life.
Both laptops and desktops will experience hardware failure earlier when exposed to constant unnecessary CPU usage. Heat increases failure rates of most internal components. Plus, a computer’s heat countermeasures include throttling down the CPU, thus making everything on the computer run slower when exposed to constant unnecessary CPU usage.
So while these issues are most immediately pertinent to laptop battery life, they do have other broader negative effects.
Between this and your Time Machine saga of things unnecessarily chewing up battery life, it’s worth remembering that this isn’t *purely* an issue that only pertains to battery life.
Both laptops and desktops will experience hardware failure earlier when exposed to constant unnecessary CPU usage. Heat increases failure rates of most internal components. Plus, a computer’s heat countermeasures include throttling down the CPU, thus making everything on the computer run slower when exposed to constant unnecessary CPU usage.
So while these issues are most immediately pertinent to laptop battery life, they do have other broader negative effects.
Then we may need to open a random album page to make sure we are not in the front page of iTunes Store.
Maybe apple can rewrite their code to consume less CPU to display that top constantly rotating banner.
Then we may need to open a random album page to make sure we are not in the front page of iTunes Store.
Maybe apple can rewrite their code to consume less CPU to display that top constantly rotating banner.
I have 2010 iMac. if I leave iTunes open to the store it uses only 20% CPU.
I have 2010 iMac. if I leave iTunes open to the store it uses only 20% CPU.
Am I missing something here? Shouldn’t OS X recognize that the page is not active and pause all that background refreshing? I would have expected that was a part of Yosemite if not ElCap.
Am I missing something here? Shouldn’t OS X recognize that the page is not active and pause all that background refreshing? I would have expected that was a part of Yosemite if not ElCap.
This story is now bouncing around the web, but is it really an accurate description of what’s going on? In the first screenshot, the CPU is 82% idle, so isn’t iTunes only using 46.9% of the 18% active user/system CPU? In the 2nd examples, it’s only using 7% of the active 5%. Maybe that’s still a lot, or maybe I’m reading it incorrectly, I don’t know, but the stories out there are all saying it’s using 50% of the CPU, which seems wrong.
It is using 46% of one core. The MacBook has four cores. It is not using 46% of the total CPU, but it is still an inordinate amount of CPU and power to be used.
Kirk, you have to turn the spell check core* back on! 😉
* I assume “for chorus” means 4 cores.
🙂 Yeah.
Fixed, thanks. It was a voice-o.
This story is now bouncing around the web, but is it really an accurate description of what’s going on? In the first screenshot, the CPU is 82% idle, so isn’t iTunes only using 46.9% of the 18% active user/system CPU? In the 2nd examples, it’s only using 7% of the active 5%. Maybe that’s still a lot, or maybe I’m reading it incorrectly, I don’t know, but the stories out there are all saying it’s using 50% of the CPU, which seems wrong.
It is using 46% of one core. The MacBook has four cores. It is not using 46% of the total CPU, but it is still an inordinate amount of CPU and power to be used.
Kirk, you have to turn the spell check core* back on! 😉
* I assume “for chorus” means 4 cores.
🙂 Yeah.
Fixed, thanks. It was a voice-o.
I notice that you have a kernel task using a significant portion of CPU as well. I have this mysterious kernel task as well, on my 2013 iMac 27″. It has plagued me across Lion, Mountain Lion, Mavericks, Yosemite, and El Cap. It eats up CPU cycles like candy and constantly uses an entire gig of my RAM. I have asked senior tech support at Apple, and they don’t know what the kernel task is or does…do you have any idea?
kernel task is a process that includes a lot of the low-level system stuff. If yours is very high, I’d check to see which third-party apps might be causing it. Look in the Launch Agents and Launch Daemons folders in your user’s Library folder, and in the top-level Library folder for files that cause background processes to launch.
I notice that you have a kernel task using a significant portion of CPU as well. I have this mysterious kernel task as well, on my 2013 iMac 27″. It has plagued me across Lion, Mountain Lion, Mavericks, Yosemite, and El Cap. It eats up CPU cycles like candy and constantly uses an entire gig of my RAM. I have asked senior tech support at Apple, and they don’t know what the kernel task is or does…do you have any idea?
kernel task is a process that includes a lot of the low-level system stuff. If yours is very high, I’d check to see which third-party apps might be causing it. Look in the Launch Agents and Launch Daemons folders in your user’s Library folder, and in the top-level Library folder for files that cause background processes to launch.