Is there a fix to kernel_task high cpu when connecting external monitor

APPLE WILL YOU FIX THIS PLEASE!!!!!! Good to know everyone is having the same issue with an external monitor. This is ridiculous and cannot work this way!!!!

Sounds like a bad dongle.

Hello, exactly same Macbook Pro and config than yours, using a BenQ external monitor for months with it and no problem until... the Ventura 13.6.7 update.

I tried everything, MVRAM and SMC updates, my external monitor is connected with USB-C directly to my Mac and also tried with HDMI.

Kernel_task running up to 800%!!!

I'm sure that dust could be a problem with high kernel_task, but there is something else going on here. I also have a 2017 MacBook Pro and I have the same problem. I took it to Apple and they blamed my old battery and suggested replacing it (the battery apparently swells when it gets old). The machine was opened, cleaned, the battery replaced and the computer passed all their tests. However, when back at home plugged into the external monitor, the problem with kernel_task was back and it renders the computer virtually unusable. I've been a long time Apple customer and I loved this laptop when I first bought it, but it has been piece of junk in the long run. It had keyboard issues, which Apple wanted nearly $1,000 to replace. I've tried all the suggested fixes, but nothing works.

First, you should update macOS since you are several updates behind now as Ventura is now at 13.4.

Next, disconnect all devices connected to the external Display(s).

If you still have the issue, then disconnect all other external devices in case one of them is causing a problem or a compatibility issue with the display.

Make sure to connect the display directly to the Mac. And try another USB-C port especially on the other side of the laptop. And like @etresoft mentions, try another cable and adapter for the monitor. And try using another video input on the external display. If you are using USB-C on the display, then try HDMI or DVI/VGA depending on the options to see if it makes any difference. FYI, not all USB-C ports on the monitors are the same so make sure to check the documentation for the external display to make sure you are connecting it properly (same goes for cables & adapters).

BobHarris wrote:

You Mac is over heating.

If kernel_task is using a large percentage of your Mac CPU - Apple Support

Start by having the dust cleaned from the inside of your Mac.

When I tried to use this link it is unable to find the correct page because it adds an extra blank space character "%20" to the URL. Just in case people have trouble with the link @BobHarris provided, here it is again, hopefully without the same issue:

If kernel_task is using a large percentage of your Mac CPU - Apple Support

If this link still is unable to work, then just enter the article number "102172" in the search box on the Apple website.

nsbm60 wrote:

I've tried all the suggested fixes, but nothing works.

Don't buy those cheap video dongles on Amazon. Get one from Apple. If that doesn't fix it, get a better monitor.

nsbm60 wrote:

Neither of those are relevant here.

You said, "when back at home plugged into the external monitor".

Also, works just fine with my Windows desktop.

That is not relevant here.

Well, what do you know!! Looks like a simple switch of my USB-C hub dongle may have indeed solved the problem. I have a 2017 MBP 15in, 2.9 GHz intel quad core i7, Radeon Pro 560 4GB, 16GB 2133MHz RAM running Ventura 13.6.7. Recently replaced the battery through an Apple certified shop.

Been having this problem for 3+ weeks now. Seemed to be triggered by Zoom calls. Could not understand why it just started happening. Updated to Ventura 13.6.7 but problem persisted. Had to keep disconnecting my LG Ultrawide ext monitor which I have had for a few years and never experienced this.

I just replaced the Vava USB-C hub and reconnected the monitor. So far, 15 mins later, kernel_task is <15%. I will return to edit if anything changes. Fingers crossed!

UPDATE: This was a temporary relief. Problem seemed to have disappeared for several days but returned. Only thing consistent is that once it starts, if I disconnect the external monitor, it immediately dissipates. Cannot figure out the triggering event. I am now connected with an Apple dongle to USB-C HDMI on one port and the other adapter to another port to support my other peripherals (external camera, printer etc). Been quiet for a couple of days. Watching carefully for the triggering event (probably multi-video stream zoom event).

You added an external monitor, so now the GPU and CPU have to work harder. That generates heat as a byproduct. Since something is preventing your Mac from removing that heat fast enough, kernel_task is stepping in to allow your GPU and CPU to cool down before they melt inside (literally melt).

You Mac is over heating.

If kernel_task is using a large percentage of your Mac CPU - Apple Support

Start by having the dust cleaned from the inside of your Mac.

Neither of those are relevant here. Also, works just fine with my Windows desktop.