rMBP kernel_task spikes when connecting more than one external monitor

When connecting a second external monitor kernel_task spikes to 600%+. This makes the computer unusable.

Here are the specifics:

• When I connect one monitor to either DP or HDMI things work fine.


• When I connect a second monitor with either DP or HDMI kernel_task spikes.


• When I disconnect either the DP or HDMI sometimes the kernel_task rapidly returns to normal levels.


• When I disconnect all monitors the kernel_task rapid returns to normal levels. (In Activity Monitor goto View > Update Frequency > Very Often and as soon as you disconnect the monitors, you will get lots of rapid updates to the UI).

What I have tried:

• Resetting NVRAM.


• Resetting SMC.


• Attempting the above scenario with power adapter plugged in and running on battery.


• Disabling "Automatic Graphics Switching" in Energy Saver.

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I am running a MacBook Pro Retina 2.7Ghz i7 (Macbook10,1 / Mid 2012) running Yosemite 10.10.1.

I have 3 external monitors (Dell 2415H) with 2 connected by Display Port and 1 with the HDMI.