Hacker News Reader

Comment by arm | Hacker News Reader

That problem you’re having with kernel_task is probably due to this¹:

“Activity Monitor may show that a process named kernel_task is using a large percentage of your CPU, and during this time you may notice a lot of fan activity. This process helps manage temperature by making the CPU less available to processes that are using the CPU intensely. In other words, kernel_task responds to conditions that cause your CPU to become too hot. When the temperature decreases, kernel_task automatically reduces its activity.”

There’s a high chance it’s reaching these temperatures so easily due to dust buildup in the MacBook. If it’s possible to open it up, I’d recommend doing so and dusting it out. If it’s not possible to open it up, you may have to take it to an Apple Retail Store and have them do it for you.

――――――

¹ — https://support.apple.com/HT203184

View on HN

I doubt it is dust if they've only had the machine "months."

MBPs with discrete graphics cards often overheat and have for literally years, Apple shouldn't even sell them until they resolve the issue but they continue to do so... It is one scenario where the cheaper integrated graphics (Intel Iris Pro) make MBPs better machines.

I've brought this up before and people anecdote me to death, but that's always been my experience, the top end MBP with discrete graphics cannot cool fast enough and throttles like crazy.

For sure the graphics runs way too hot, but it will overheat even when running on integrated graphics.

You absolutely need to install Flashblock in your browsers (remember Chrome includes Flash). All the Flash based trackers and ads showing in your browser quickly drains the battery and often places a huge demand on the GPU.

Or simply select Settings => Show advanced => Content Settings => Plugins: Let me choose when to run plugin content

I think there are more and more HTML5 video ads though, so you also need uBlock Origin.

If the OP smokes there could be enough of a buildup to cause an issue.

> MBPs with discrete graphics cards often overheat and have for literally years

If you're hammering the GPU of course it's gonna create a lot of heat. Then the system will react to cope with that heat. What else do you expect to happen?

The integrated Intel GPU is slow by comparison. If you're happy with that there are hacks out there to tell the system to always use it and not use the discrete GPU but that seems really silly to me.

You're missing the point, of course hammering the GPU creates a lot of heat, but you would expect a high end system that came pre-packaged with the GPU to be able cope with the heat. If the system is overheating, clearly it is not coping very well.

Packaging hardware into a system without sufficient cooling to actually use it at capacity is just bad design.

The CPUs work the same way, my friend. If you hammer one core to its full capacity it will get throttled too. It's just how CPUs and GPUs are designed. They give you an option to "overload" them for a short time, and then they scale back to a sustainable level. Would you rather they only let you use them up to the sustainable level?

Desktop GPUs and CPUs work the same way.

But don't all modern MBPs have both an integrated and discrete graphics card? Mine sure does. So when I'm not doing something graphics-intensive, my 15" MBP uses the Iris Pro graphics.

I can't say I've experienced the described behavior except on rare occasions when I need to find a rogue task and kill it.

Check out gfxCardStatus. To be fair, some apps (IntelliJ IDEs + Java6 cough) seem to force it into using the discrete graphics card but even then I don't get the spinning-fan-slow-to-a-crawl behavior.

I would take it back. I had this problem in and older MBPr that had been in for a recent board replacement under Apple Care. Turned out the new board was actually faulty. They replaced it with a brand new machine again entirely under Apple Care.

I second that your experience is inconsistent with what I've seen and had myself. I think it would be worthwhile to send it in for repair to Apple under the assumption of faulty hardware.

Forgot to mention, I already cleaned it out, it had some dust, temp fell maybe a few degrees.

I've had this issue (during and after GPU-intensive tasks, which aren't common enough to be a major nuisance), and after blowing compressed air through all exposed vents, didn't notice a change. I should schedule a repair time at a retail store to see if that fixes the issue.

A jury-rigged stopgap that is surprisingly effective for me is setting the metal-bodied laptop on top of an liquid icepack for a few minutes. kernel_task drops to background noise and I can continue working.

It's supposedly unsafe to use an air compressor on a laptop because of concerns of static buildup, but I did that with mine that was full of dust and it worked great afterwards.

Reply on news.ycombinator.com