CPU usage at 50% when idle

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Level 4

2,857 points

CPU usage at 50% when idle

I downloaded System Activity monitor, and I am seeing over 50% utilization on an idle iPhone. I tried restoring, resetting, turning on and off, but something is running and I can't tell what. Running processes are:

0 kernel_task
1 launchd
13 syslogd
14 lockdownd
15 mediaserverd
16 mDNSResponder
19 fairplayd
20 configd
22 accessoryd
23 SpringBoard
27 CommCenter
28 BTServer
29 aosnotifyd
30 notifyd
51 MobilePhone
52 MobileMail
57 ptpd
59 afcd
61 afcd
63 notification_pro
127 apsd
226 MobioleMusicPlaye
258 System

For not being able to run background processes, the iPhone sure is busy doing nothing. 🙂 Any ideas?

iPhone 3GS, Windows XP Pro

Posted on Jul 14, 2009 6:20 PM

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Answer 1

w7ox

Level 4

2,407 points

Jul 14, 2009 6:32 PM in response to PTBoater

I use System Activity Monitor. I notice a high level of CPU activity just after I do a Reset or power back up after the 3GS being off -- as much as 70% (30% idle).

But if it sits in Sleep, or even is used, for a couple of hours my Idle time rises steadily and ends up at a high value (just now it reads 98.65%).

What to make of this? I don't have a clue. But do run that program after your 3GS has been sitting in standby for a couple of hours.

Update: Here's an earlier thread I started on this topic

http://discussions.apple.com/thread.jspa?threadID=2078620&tstart=150

Phil

Message was edited by: w7ox

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Answer 2

w7ox

Level 4

2,407 points

Jul 14, 2009 6:54 PM in response to PTBoater

I had a similar concern and thought it related to a specific application (decided later it did not). Thread is here:

http://discussions.apple.com/thread.jspa?threadID=2077565&tstart=0

If the high CPU activity after being Off (not sleeping) really means more power consumption there some interesting implications. For instance, turning it off for a few hours to save power may be a poor strategy compared to just letting it sleep, if it alway draws higher power for a couple of hours after being turned on.

I expected a reset to shut down apps and reduce the power consumption but just the opposite happened.

So I now have a practice of checking System Activity Monitor after running any new app, just to see if it has significantly reduced idle time. So far none has.

Phil

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Answer 3

PTBoater Author

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Jul 14, 2009 6:36 PM in response to w7ox

Thanks for the tip. I will observe it over the next couple of days to see what happens. I have been reading all the threads and was curious since I am getting one full day of use with both the iPhone battery and the Mophie Juicepack. So basically I am running out of juice around 2pm. I think half of my problem is I am using it too much 🙂 but today I tried not using it at all (just standby) and I went from 100% when I unplugged it at 7am to about 60% at 4pm. And I did NOTHING with it, maybe one phone call less than 1 minute. That just seems wrong. I am wondering if some rogue app is causing this.

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Answer 4

PTBoater Author

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2,857 points

Jul 15, 2009 5:53 AM in response to w7ox

Its been 12 hours since I did my last full charge and posted this thread. I have observed some VERY interesting behavior.

1. CPU utilization has not dropped below 30%. It is made up of 7-9% System Utilization and 20-22% User utilization. That means idle has never exceeded 70%. Always in the mid-high 60s.

2. Battery has gone from 100% to 95% in 12 hours. I was mostly sleeping, and usage stats reads 11 hours 28 minutes standby and 20 minutes usage. That seems more like it!!!

3. I turned off WiFi, Bluetooth, push, fetch, and notifications. I just wanted to see how fast it would drain. I will drain it fully and then recharge and test again with some of these turned on.

So my guesses are:

1. My battery is fine.

2. System Activity Monitor may be affected by some other installed app. I can think of no other explanation why my utilization is always so high when others are reporting 1-2%.

Any other ideas?

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Answer 5

w7ox

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2,407 points

Jul 15, 2009 6:35 AM in response to PTBoater

PTBoater wrote:
Its been 12 hours since I did my last full charge and posted this thread. I have observed some VERY interesting behavior.

1. CPU utilization has not dropped below 30%. It is made up of 7-9% System Utilization and 20-22% User utilization. That means idle has never exceeded 70%. Always in the mid-high 60s.

Yes, "interesting". I've not seen that high a level of CPU activity over such a long period of time. I've read that only resident, built-in apps can run in the background. I wonder if one of those is the cause?

I hope a future version of the utility will provide info on CPU usage by process.

2. Battery has gone from 100% to 95% in 12 hours. I was mostly sleeping, and usage stats reads 11 hours 28 minutes standby and 20 minutes usage. That seems more like it!!!

That does sound good.

3. I turned off WiFi, Bluetooth, push, fetch, and notifications. I just wanted to see how fast it would drain. I will drain it fully and then recharge and test again with some of these turned on.

So my guesses are:

1. My battery is fine.

2. System Activity Monitor may be affected by some other installed app. I can think of no other explanation why my utilization is always so high when others are reporting 1-2%.

My impression is that 3rd party apps cannot run in the background. But I have no technical info to back that up. I know an iPhone developer and will ask him.

Phil

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Answer 6

Randy Fast

Level 4

1,432 points

Jul 15, 2009 6:43 AM in response to PTBoater

Those are all system processes and normal. For instance without Springboard running you wouldn't see anything on the home screen or be able to launch apps. Without fairplay running you wouldn't be able to play songs on the iPod. Kind of like looking at the dozens of system processes running all the time on your computer.

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Answer 7

PTBoater Author

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2,857 points

Jul 15, 2009 9:12 AM in response to Randy Fast

Ok, so I lost patience when 1 1/2 hours went by and the battery went down only 1%. At this rate, it would be DAYS before the battery drained. 🙂

So at 94% I plugged it back in, charged it fully, and:

Turned on bluetooth, wifi (join off), notifications (3 apps, AP, Zillow, and BeeJive), push (MobileMe Mail and Calendar/Contacts). No other mail accounts.

Its been one hour, and the thing is still at 100%.

The WEIRD part is that CPU utilization is DOWN to less than 20%. 13% user and 5% system +/- 1%. I am not sure what that means. With years of troubleshooting experience, I am stumped.

Let me see if I can keep my hands off the iPhone for the rest of the day. All in the name of science.... 🙂

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Answer 8

w7ox

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Jul 15, 2009 10:31 AM in response to PTBoater

PTBoater wrote:

Let me see if I can keep my hands off the iPhone for the rest of the day. All in the name of science.... 🙂

You didn't actually buy it to make phone calls, did you? 😉

Phil

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Answer 9

PTBoater Author

Level 4

2,857 points

Jul 15, 2009 1:51 PM in response to w7ox

w7ox wrote:
You didn't actually buy it to make phone calls, did you? 😉

Phil

What? The iPhone can make phone calls too??? 😉

5 hours, and I am down 5%. Tracking for 100 hours, not 300, but I have push, notifications, bluetooth and wifi on. But that is without using it. And I have not forwarded all my email accounts to my MobileMe push account, so I haven't seen any email traffic. Seems about right.

The adventure continues....

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Answer 10

PTBoater Author

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Jul 15, 2009 6:16 PM in response to PTBoater

10 hours, 8 minutes standby, 38 minutes usage, down to 84%. I am not going to get to 100 hours.

A friend came over and had to give him a demo. Used the GPS a bit, took a couple of pics, a little music/video, about 20 minutes of what I would call "heavy usage". I just could not keep my hands off it... 🙂

If I can get 16 hours out of it, I will be happy. I've had a couple of BlackBerries and consider myself a heavy user, and I could make it through the day on a single charge, and got into the habit of recharging every night. By the time I have exhausted the recharge cycles, the iPhone 4GX will be out... 🙂

Utilization, interestingly enough, has dropped to below 20%. 12% user and 6% system. This time I will drain the battery before I recharge. I think I have enough self control for THAT. (self control and a Mophie Juicepack.. 🙂 )

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Answer 11

Jul 15, 2009 9:39 PM in response to Randy Fast

Randy Fast wrote:
Those are all system processes and normal.

I believe "MobioleMusicPlaye" (MobileMusicPlayer) is an app downloaded from the App Store and is therefore not a system process, but a third-party application running in the background somehow.

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Answer 12

PTBoater Author

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Jul 16, 2009 11:41 AM in response to Xian Rinpoche

I seem to recall MoibleMusicPlaye being identified as the iPod, so I just went in to check, and my utilization is down to less than 8%!!! (4.5% user, 3% system). So weird. And MobileMusicPlaye is not on the list.

I exited, clicked on the iPod, started a song, went back to Activity Monitor, and sure enough, MobileMusicPlaye appeared. The description says "iPod".

Funny thing is utilization remained unchanged as I listened to Abba. I remain stumped.

Battery is down to 9% after 27 hours standby and 4 1/2 hours of usage. I did try out Google sync (using Exchange sync) for about 1/2 hour until I decided to stick with MobileMe. Also downloaded and messed around with a drums simulation. This kind of battery consumption for this kind of use seems reasonable to me.

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Answer 13

PTBoater Author

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Jul 16, 2009 3:39 PM in response to PTBoater

Ok, battery is charged back up to 100%, and utilization is down to less than 4% (less than 2% each user and system). This whole utilization thing baffles me.

I will start doing the battery logging now and see what that yields. I am going to route all my mail to my MobileMe account and leave push and notifications on to simulate more realistic use. I am also syncing calendars and contacts with MobileMe using push, but I dont do much on those.

If I could only stay out of the AppStore for 24 hours... 😉

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Answer 14

w7ox

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Jul 16, 2009 4:43 PM in response to PTBoater

PTBoater wrote:
Ok, battery is charged back up to 100%, and utilization is down to less than 4% (less than 2% each user and system). This whole utilization thing baffles me.

Yeah, me too. I thought a reset would shut things down. Instead utilization of CPU started at 70% after and went down as the iPhone sat in sleep. Mine now shows 0.68% user and 0.93% system -- and 0.00% "Nice" whatever that is!

I hope a later version of the app tells you how much CPU is being used by each process.

Funny: My screen seemed unusually bright. Then I realized my eyes are still dilated from seeing the ophthalmologist several hours ago (four different doses of drops).

Phil

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Answer 15

w7ox

Level 4

2,407 points

Jul 17, 2009 7:24 AM in response to PTBoater

I just ran iTunes and there was a new version of System Activity Monitor available.

Installed it and now I see more significant swings in CPU activity -- more like I see in other computers. The graphic displays shows short spikes and such. Could be due to having just synced and updated 8 apps .. or maybe the program has been modified to better reflect reality.

SAM also now starts in the Memory screen vs. the screen where I last used it.

Phil

Message was edited by: w7ox

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