Intel HDMI monitor not recognized

Question

The problem

I've got two graphics cards in my computer:

• Nvidia GTX 580
• Intel Graphics (onboard)

The Nvidia part is working fine: plugged in a DVI cable to my monitor and everything works perfectly. The Intel part is totally ignored. xrandr says it is disconnected, and even tty is not visible at the Intel/HDMI display.

When having xf86-video-intel installed, my monitor says no signal, if it is uninstalled, it says 1024-768 connected with a black screen. (completely black, no tty)

Information

I am using Arch Linux.

After installing xf86-video-intel I also added to /etc/mkinitcpio.conf the i915 tag in the MODULES line: MODULES="i915"

Calling uname -r gives me: 3.14.25-1-lts

Calling lscpi -v gives me (among other things):

00:02.0 Display controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) Subsystem: ASRock Incorporation Device 0122 Flags: bus master, fast devsel, latency 0, IRQ 45 Memory at f7400000 (64-bit, non-prefetchable) [size=4M] Memory at d0000000 (64-bit, prefetchable) [size=256M] I/O ports at f000 [size=64] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 2 Capabilities: [a4] PCI Advanced Features Kernel driver in use: i915 Kernel modules: i915

Calling xrandr gives me:

Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 8192 x 8192 DVI-I-1 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm 1920x1200 59.95*+ 1600x1200 60.00
1280x1024 75.02 60.02
1280x960 60.00
1152x864 75.00
1024x768 75.08 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 60.00
720x400 70.08
DVI-I-2 disconnected (normal left inverted right x axis y axis) HDMI-4 disconnected (normal left inverted right x axis y axis)

Possible causes which are not the cause

• The cable is not the problem. It runs perfectly fine booting on Windows.

Answer 1

I'm no expert, but as far as I know, on board graphics are always disabled when you add a video card. I run three monitors, and I've set up dual monitors on several machines, but I have never once got the onboard video to work at all once addon cards are inserted. I'd love to be mistaken about that.

Answer 2

The BIOS is responsible for deciding whether or not the IGD is enabled when a graphics card is present. However, nvidia and Catalyst may not allow "rebuffering" of the graphics card output into the IGD buffer even when the IGD is enabled.