MacOS – Prevent photoanalysisd from spinning up fans

This is the common problem which can be related to anything, like:

• Chrome bugs,
• network issues (check logs at chrome://net-internals/),
• active extensions are slowing down web browser in general,
• performance issues (either your machine is slow or you've too many tabs opened),

• slow disk access, especially when your cache folder is huge with too many files.

  E.g. you may consider moving your profile folder into quick access drive.

Here are few suggestions:

• restart web browser (also kill all chrome processes),
• run in Incognito mode, to see if this could be related to some slow extensions,
• create a new profile with no extensions and see if that helps,
• install addons which aims limit the page processing (e.g. OneTab, ad blockers),
• run Chrome in different user data dir (--user-data-dir="<some_path>"),

• run with --disable-hang-monitor to suppress hang monitor dialog,

  Suppresses hang monitor dialogs in renderer processes. This may allow slow unload handlers on a page to prevent the tab from closing, but the Task Manager can be used to terminate the offending process in this case.^peter.sh

• make sure Chrome uses GPU process to enhance performance (see: chrome://gpu/),
• generate network log file at chrome://net-internals/ and report the issue at bugs.chromium.org.

Debug suggestions:

• check: chrome://flags/
• check debug network log file generated by chrome://net-internals/
• run chrome://tracing/
• see other internal Chrome pages at chrome://chrome-urls/.

You have classic symptoms that thermal issues are causing kernel task to preemptively use up CPU to prevent overheating. If you haven't reset the SMC, try that one time. If the System Management Controller is actually stuck, the response to changing thermal measurements might lag or leave blowers on higher than they should be.

• kernel_task hundreds of % CPU yet cpu frequency is being lowered
• CPU usage is too high with Yosemite and an external monitor
• kernel_task consumes 500% CPU on AC power, sometimes
• MBP early '11 kernel_task over 300% when unplugged
• MacBookAir kernel_task at 300% and rising

The answers above all point to things you can do to measure swap, processes, etc... but focus on thermal sensors (hardware issue) or external temperature (environment) which you can cool artificially to remove the slow down that's designed to manage heat.

If you can't measure the case temperature accurately with an infrared thermometer, try software like https://bjango.com/mac/istatmenus/ to check on the individual temp sensors and correlate them with the "spikes in CPU usage" by kernel_task. Also, resetting the SMC one time might be worth your while. If it's stuck, the response to changing thermal measurements might lag or leave blowers on higher than they should be.