Computer slows down when connected to external monitors
I am working on a MacBook Pro that has dual GPUS (Intel Iris & AMD Radeon)
The user uses 2 external monitors.
His computer starts slowing down, the kernel usage gets to 87% and oddly bounces as high as 240 %. The laptop is a bit warmer than usual but no thermal problems. The user reports that when this problem started that it was about 1 hour or so before the computer slows down; it is now starting to slow down in about 5 minutes.
The user has reset the PRAM and also SMC reset but no change.
Is this a hardware failure? Thanks
Having experienced this issue myself using a MBP with 2 x LG LED 24EN43 monitors; I read these comments with interest. Although not mentioned, I just unplugged the monitors and went to System Preferences/Displays/Colour then hit the Calibrate button. That was a perfect fix. Everything works like brand new! Hope this helps you too.
Another useful tip from...
由 Chris Williams-Lilley 完成的
Sorry mate, I don't see how color calibration (which is just a software profile) would affect the CPU performance, especially when I (I don't know about the others) am experiencing this issue even on boot camp in Windows! Regardless, I tried your suggestion, and it made absolutely no difference; after 30 seconds the laptop was throttling again.
由 Alexandros Vernardis 完成的
He means that he 'disconnected' permanently monitors and calibrated his laptop instead :) Never connected them back ;)
由 greg.goray 完成的
In my particular case, I actually found out after lots of frustration that my laptop power cord has an issue and while it was connected, I had to bend the cord this way or that in order to have it actually charging. When I took the power cord out of the equation, everything returned to normal. I'm running 3 external monitors...one through an external USB-based video card that I'm using 1 DVI port, one through the existing laptop HDMI port and one through the existing laptop VGA port. Up until my issues this afternoon, all 4 screens worked flawlessly...then all of the sudden it was like my computer was bogged down with too many tasks...just moving the mouse across the screen was a multi-minute chore...so, if anybody else is troubleshooting, as strange as it sounds...check that your power cord is working properly.
由 thewasel 完成的
I was able to fix the problem by matching the display resolution for both monitors. When the laptop monitor and the usb monitor were the same resolution there was no slowing.
由 Todd Helfman 完成的