How many displays I can use at the same time?

Question

I know from xrandr command, that my graphic card supports maximum resolution of 16384 x 16384px:

$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384

But how can i check how many outputs can I use at the same time? I was using 2-3 years ago one command that was giving me that number, but I can't recall it now.

I found similiar questions, but none of it are accurate or give universal method:

• How many monitors can I attach?
• How many monitors can i connect to this gpu

Answer 1

I used grep on my 11k lines of commands' history and finally found it:

$ xrandr --listproviders
Providers: number : 1
Provider 0: id: 0x48 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 4 outputs: 5 associated providers: 0 name:modesetting

It tells us, that this graphic card have max 5 outputs (internal display, VGA, 3x DisplayPort), but at the same time this laptop can use only 4 of them (crtcs).

Above output is an example for configuration:

$ sudo lspci -vnn | grep VGA -A 16
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK106GLM [Quadro K2100M] [10de:11fc] (rev a1) (prog-if 00 [VGA controller])
    Subsystem: Dell GK106GLM [Quadro K2100M] [1028:05cc]
    Flags: bus master, fast devsel, latency 0, IRQ 32
    Memory at f5000000 (32-bit, non-prefetchable) [size=16M]
    Memory at e0000000 (64-bit, prefetchable) [size=256M]
    Memory at f0000000 (64-bit, prefetchable) [size=32M]
    I/O ports at e000 [size=128]
    Expansion ROM at 000c0000 [disabled] [size=128K]
    Capabilities: [60] Power Management version 3
    Capabilities: [68] MSI: Enable+ Count=1/1 Maskable- 64bit+
    Capabilities: [78] Express Endpoint, MSI 00
    Capabilities: [b4] Vendor Specific Information: Len=14 <?>
    Capabilities: [100] Virtual Channel
    Capabilities: [128] Power Budgeting <?>
    Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?>
    Capabilities: [900] Secondary PCI Express <?>
    Kernel driver in use: nouveau

I know, that this laptop have also Intel graphic card, but disabled in BIOS. I will check later what is output of this commands when second graphic card is enabled.