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Tom B

Member

Registered: 2014-01-15

Posts: 187

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Hybrid Graphics PRIME: Use dedicated card for external display only

I have a Macbook Pro with two gpus:

[tom@io ~]$ xrandr --listproviders
Providers: number : 2
Provider 0: id: 0xa3 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 6 outputs: 4 associated providers: 0 name:VERDE @ pci:0000:01:00.0
Provider 1: id: 0x48 cap: 0xb, Source Output, Sink Output, Sink Offload crtcs: 4 outputs: 5 associated providers: 0 name:Intel

0 is a Radeon M370X and 1 is the intel graphics. I can switch graphics card using the gpu-switch utility and reboot. Unfortunately as it mentions on the MacBook Pro 11,x wiki page  "Note that the HDMI port and MiniDP are soldered to the nvidia card meaning that to run external displays you need to use the dedicated card." which also seems to apply to this model with a Radeon card.

I don't need to do anything graphically intensive, but I do need to use an external display from time to time. I can only use an external display when I have the Radeon card as the primary GPU, is there any way to allow the Radeon card to become active only when an external monitor is connected? (Or ideally if I do run a graphically intensive program).

At the moment when using the Intel graphics as the primary card via gpu-switch I cannot use the external display, which means I have to use the radeon graphics all the time, sacrificing battery life and the laptop runs rather hot (60C idle, using intel graphics it idles at 45-50C). Is there any way to keep the radeon card enabled and have it used if/when it's required for an external display?

Lone_Wolf

Forum Moderator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 11,925

Re: Hybrid Graphics PRIME: Use dedicated card for external display only

Only option i can think of that may help you is Reverse Prime.

That will allow the intel card to render for displays connected to the radeon card.

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Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

(A works at time B)  && (time C > time B ) ≠  (A works at time C)