Macbook 2015 and 4k Monitor or kernel_task eats all memory?

Question

macbook

Available:
1) Macbook "15 2015
2) Old 24" monitor.
3) 4K 27" monitor (LG UltraFine 27UL650)

I came up with the idea to make a system unit out of it, since there is no money on iMac yet :D
I bought a 4K Monitor for 27", a wireless keyboard and mouse. I connected a 4K monitor via DisplayPort, and an old monitor via HDMI. I slammed the lid, looked at the temperature readings - it didn’t seem to get warm. I used it for several days in normal Internet browsing mode, everything is fine, I’m happy elephant, 4K monitor is fine, wireless keyboard takes up little space, freed up a lot of space on the desktop - everything is fine. But as soon as I sat down to work, run resource-intensive applications or several browsers, everything slows down like hell. Even regular Chrome with Developer Tools enabled lags like I launched it on an old pentium.

In the processes, kernel_task is launched and loads by 300-500%, the whole system slows down. As I found out, this process starts, protecting the laptop from overheating, taking some of the load from the processor onto itself. Processor temperature - 60-70 degrees, not higher. I turned off both monitors, everything works fine, the percentage heats up to 90+ degrees, everything flies.

What could be the problem? My thoughts are as follows:

1) The MacBook is old and no longer pulls 4K, you need to change it to something newer.
2) The video card does not pull and it makes sense to buy an external one.
3) You should clean the laptop from dust, it may be trying to overheat because of this.
4) Fuck kernel_task

Answer 1

1) The MacBook is old but pulls 4K, you need to connect it with a high-quality mDP-> DP cable (or even mDP-> mDP, in my opinion, is it bundled with a monitor? I had the same one half a year ago, my eyes got tired of it terribly, after 3 months I had to sell it for almost half the price ...)
2) It makes sense to start by forcibly turning on a discrete video card, since the integration is most likely working for you now. Go to settings - power consumption and there will be a checkmark at the top "switch video cards automatically" - remove it. And watch the results
3) You should clean the laptop from dust, at least once a year this must be done. And also replace the thermal paste with some kind of normal one, after all, the laptop is 5 years old ... (the main thing is not to take liquid metal, they are not compatible with the cooling of macbooks, mx-4 works a little better than the native Apple one, but it doesn’t matter)
4) Fuck kernel_task If it doesn't work, it will restart.

Answer 2

.*? - this means that any character will eventually end :)
In general, use + instead of *. Otherwise there is even [].
/\[.+?\]/

Answer 3

If only lat. letters, then a-zA-Z is everything.*

Answer 4

/\+\]/