I have a new Debian machine and I'm trying to attach a second monitor to it. When I plug it into my HDMI port, the second monitor duplicates the first monitor, while I would like to extend it.

My machine is a Dell Inspiron 15 7537 (http://www.dell.com/uk/p/inspiron-15-7537/pd).

To provide some details, the output of uname -a is

Linux marcoshstudio 3.16-0.bpo.3-amd64 #1 SMP Debian 3.16.5-1~bpo70+1 (2014-11-02) x86_64 GNU/Linux

The output of lspci -nn is

00:00.0 Host bridge [0600]: Intel Corporation Haswell-ULT DRAM Controller [8086:0a04] (rev 0b)
00:02.0 VGA compatible controller [0300]: Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a16] (rev 0b)
00:03.0 Audio device [0403]: Intel Corporation Device [8086:0a0c] (rev 0b)
00:14.0 USB controller [0c03]: Intel Corporation Lynx Point-LP USB xHCI HC [8086:9c31] (rev 04)
00:16.0 Communication controller [0780]: Intel Corporation Lynx Point-LP HECI #0 [8086:9c3a] (rev 04)
00:1b.0 Audio device [0403]: Intel Corporation Lynx Point-LP HD Audio Controller [8086:9c20] (rev 04)
00:1c.0 PCI bridge [0604]: Intel Corporation Lynx Point-LP PCI Express Root Port 1 [8086:9c10] (rev e4)
00:1c.2 PCI bridge [0604]: Intel Corporation Lynx Point-LP PCI Express Root Port 3 [8086:9c14] (rev e4)
00:1c.3 PCI bridge [0604]: Intel Corporation Lynx Point-LP PCI Express Root Port 4 [8086:9c16] (rev e4)
00:1c.4 PCI bridge [0604]: Intel Corporation Lynx Point-LP PCI Express Root Port 5 [8086:9c18] (rev e4)
00:1d.0 USB controller [0c03]: Intel Corporation Lynx Point-LP USB EHCI #1 [8086:9c26] (rev 04)
00:1f.0 ISA bridge [0601]: Intel Corporation Lynx Point-LP LPC Controller [8086:9c43] (rev 04)
00:1f.2 SATA controller [0106]: Intel Corporation Lynx Point-LP SATA Controller 1 [AHCI mode] [8086:9c03] (rev 04)
00:1f.3 SMBus [0c05]: Intel Corporation Lynx Point-LP SMBus Controller [8086:9c22] (rev 04)
02:00.0 Network controller [0280]: Intel Corporation Device [8086:08b1] (rev 73)
03:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device [10ec:5287] (rev 01)
03:00.1 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller [10ec:8168] (rev 12)
04:00.0 3D controller [0302]: NVIDIA Corporation Device [10de:0fe4] (rev a1)

The output of xrandr -q, with my second monitor plugged in, is

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected 1920x1080+0+0 0mm x 0mm
    1920x1080       0.0*

The output of lshw -c video is

   description: VGA compatible controller
   product: Haswell-ULT Integrated Graphics Controller
   vendor: Intel Corporation
   physical id: 2
   bus info: pci@0000:00:02.0
   version: 0b
   width: 64 bits
   clock: 33MHz
   capabilities: msi pm vga_controller bus_master cap_list rom
   configuration: driver=i915 latency=0
   resources: irq:62 memory:e3000000-e33fffff memory:c0000000-cfffffff ioport:5000(size=64)
   description: 3D controller
   product: NVIDIA Corporation
   vendor: NVIDIA Corporation
   physical id: 0
   bus info: pci@0000:04:00.0
   version: a1
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress bus_master cap_list
   configuration: driver=nouveau latency=0
   resources: irq:65 memory:e2000000-e2ffffff memory:d0000000-dfffffff memory:e0000000-e1ffffff ioport:3000(size=128)

I tried nvidia-detect, but the output is

No NVIDIA GPU detected.

Do you have any hint or suggestion on how I can manage to use both my screens?

2 Answers 2


I can't tell what your monitor names are, so adapt to this line of code. xrandr --output (mon1) --left-of (mon2)

  • xrandr can find only one screen, so I can't run such a command
    – marcosh
    Nov 23, 2014 at 14:52
  • Based on your response to Michael Durant I am assume it's a problem with your monitor. If you have another monitor somewhere that you can borrow try plugging that in. Or maybe just try a different cord if you can, preferably a different input slot. It looks like you are using VGA, am I correct?
    – user92389
    Nov 23, 2014 at 15:01
  • actually I am using HDMI, and this is the only video input slot available in my laptop. Anyway, I would exclude a monitor problem, because I can see in it the exact replica on my laptop monitor
    – marcosh
    Nov 23, 2014 at 15:13
  • Updating your video drivers is the last thing I can think of.
    – user92389
    Nov 23, 2014 at 16:04

Don't mirror windows, for example in Ubuntu you can use the display configuration gui:

Make sure your window settings DO NOT have:

Mirror Display (Note: may limit resolution options) checked, as in:


  • In my Display settings I can see just one monitor (called Unknown) and the mirror display option is disabled and not checked
    – marcosh
    Nov 23, 2014 at 14:18

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