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OS: Ubuntu 16.04 LTS
Memory: 7.7GiB
Processor: Intel® Core™ i5-5257U CPU @ 2.70GHz × 4 
Graphics: Intel® Iris 6100 (Broadwell GT3) 
OS type: 64-bit
Disk: 37.0 GB
Machine: Macbook Pro A5102
uname -a: Linux caleb-macbuntu 4.8.0-41-generic #44~16.04.1-Ubuntu SMP Fri Mar 3 17:11:16 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
uname -r: 4.8.0-41-generic
Chrome version: Version 57.0.2987.110 (64-bit)

I am exploring a dual-boot of Ubuntu on my Macbook Pro. I have noticed the system working extremely slowly when Chrome is running with reasonable tabs (5-6). Everything is much slower than when I'm running OSX on this same machine, doing far more "heavy lifting."

System monitor is showing abnormally high CPU usage, sometimes with all 4 cores at 100% when refreshing a page in Chrome. Memory is at 4.7GiB / 7 GiB, with none of my 2GiB of Swap being used.

Google searches mostly points to old threads about Chrome in general being a RAM hog, however I don't feel those are relevant because I'm running the current version, and on this same machine Chrome functions just fine. I have kept an eye on System Monitor and noticed no obvious signs of memory leakage, just that Chrome usage causes CPU spikes. I am testing with Chrome being the only process I'm running (other than system monitor and terminal).

My question is twofold: If you have observed this before and are already aware of the likely cause and solution, could you enlighten me? OR, if the answer is not obvious to you, could you give me tips in how I can investigate this issue further?

EDIT: Weirdly, when not connected to an external monitor via a DVI cables, all issues vanish. OSX doesn't mind being connected to the same external monitor. CPU usage drops to a normal ~10% across the board when using the laptop screen.

EDIT: I'm noticing that the external monitor bit may be a red herring - more likely, it seems that I get this issue when I have multiple chrome windows with different accounts - chrome windows on the same account don't seem to cause issues.

EDIT: I'm now of the opinion that all prior bits in this post about chrome, other tabs, etc are red herrings, and that the real issue is a fairly well documented issue with compiz taking buttloads of processor power to render graphics that should be handled by a videocard. I'm currently testing using this open source graphics driver and so far so good, will test for a week and leave an answer if this is the case.

EDIT: I feel like I'm going insane. It seems to be that these slowdowns ONLY happen if I move a chrome window to another desktop. So I can have infinite chrome windows on desktop 1, but if I move a single one to any other desktop, everything slows down.

EDIT: It really feels like this question here has nailed the issue on the head. I have disabled hardware acceleration in chrome (what I think the poster meant) by going to Chrome Settings, clicking "advanced settings," scrolling down to "system settings," and unchecking "use hardware acceleration when available." I will report results. The compiz bit and drivers bit I think were not the issue.

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Caleb Jay
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  • Are your CPU scaling up in frequency correctly? – Doug Smythies Mar 27 '17 at 21:03
  • @DougSmythies what do you mean by this? How can I check? – Caleb Jay Mar 27 '17 at 21:52
  • I mean that 100% load at minimum CPU frequency is very very different 100% load at maximum CPU frequency. Check via grep MHz /proc/cpuinfo when your system is under the "load" conditions you wrote about. Oh, I see you added some info to your question. Then CPU scaling is not likely to be the issue. – Doug Smythies Mar 27 '17 at 21:55

1 Answers1

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The issue was from Chrome.

I solved the issue by disabling hardware acceleration in Chrome. No negative side-effects have been noticeable.

  1. In Chrome, click the 3 dots at the top-right corner.
  2. Select "Settings"
  3. At the bottom, click "Show Advanced Settings"
  4. Scroll to the "system" section
  5. Uncheck "use hardware acceleration when available."
  6. Restart all Chrome windows.
Caleb Jay
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