I have a user who wants to have 4 monitors attached to his CentOS 6.4 system. I know that you can't use both on-board video and a PCI video card at the same time, but what about two PCI video cards? The system seems to recognize them as shown by the lspci -v output below, but I can't get Xorg to use the second card. Has anyone done this? If so, what is the trick to get it to work? Alfred 00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09) Subsystem: Dell Device 04ad Flags: bus master, fast devsel, latency 0 Capabilities: [e0] Vendor Specific Information <?> 00:01.0 PCI bridge: Intel Corporation Xeon E3-1200/2nd Generation Core Processor Family PCI Express Root Port (rev 09) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=01, subordinate=01, sec-latency=0 I/O behind bridge: 00004000-00004fff Memory behind bridge: ed000000-ee0fffff Prefetchable memory behind bridge: 00000000e0000000-00000000e9ffffff Capabilities: [88] Subsystem: Dell Device 04ad Capabilities: [80] Power Management version 3 Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [a0] Express Root Port (Slot+), MSI 00 Capabilities: [100] Virtual Channel <?> Capabilities: [140] Root Complex Link <?> Kernel driver in use: pcieport 00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04) Subsystem: Dell Device 04ad Flags: bus master, fast devsel, latency 0, IRQ 11 Memory at eebb0000 (64-bit, non-prefetchable) [size=16] Capabilities: [50] Power Management version 3 Capabilities: [8c] MSI: Enable- Count=1/1 Maskable- 64bit+ 00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (rev 04) Subsystem: Dell Device 047e Flags: bus master, fast devsel, latency 0, IRQ 32 Memory at eeb00000 (32-bit, non-prefetchable) [size=128K] Memory at eeb80000 (32-bit, non-prefetchable) [size=4K] I/O ports at 5040 [size=32] Capabilities: [c8] Power Management version 2 Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+ Capabilities: [e0] PCI Advanced Features Kernel driver in use: e1000e Kernel modules: e1000e 00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 04) (prog-if 20 [EHCI]) Subsystem: Dell Device 04ad Flags: bus master, medium devsel, latency 0, IRQ 16 Memory at eeb70000 (32-bit, non-prefetchable) [size=1K] Capabilities: [50] Power Management version 2 Capabilities: [58] Debug port: BAR=1 offset=00a0 Capabilities: [98] PCI Advanced Features Kernel driver in use: ehci_hcd 00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 04) Subsystem: Dell Device 04ad Flags: bus master, fast devsel, latency 0, IRQ 31 Memory at eeb60000 (64-bit, non-prefetchable) [size=16K] Capabilities: [50] Power Management version 2 Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+ Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00 Capabilities: [100] Virtual Channel <?> Capabilities: [130] Root Complex Link <?> Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel 00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b4) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=02, subordinate=02, sec-latency=0 Capabilities: [40] Express Root Port (Slot+), MSI 00 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit- Capabilities: [90] Subsystem: Dell Device 04ad Capabilities: [a0] Power Management version 2 00:1c.2 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 3 (rev b4) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=03, subordinate=03, sec-latency=0 I/O behind bridge: 00003000-00003fff Memory behind bridge: ee100000-eeafffff Prefetchable memory behind bridge: 00000000ea100000-00000000eaafffff Capabilities: [40] Express Root Port (Slot+), MSI 00 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit- Capabilities: [90] Subsystem: Dell Device 04ad Capabilities: [a0] Power Management version 2 00:1c.4 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 5 (rev b4) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=04, subordinate=04, sec-latency=0 I/O behind bridge: 00002000-00002fff Memory behind bridge: eb000000-ec0fffff Prefetchable memory behind bridge: 00000000d0000000-00000000d9ffffff Capabilities: [40] Express Root Port (Slot+), MSI 00 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit- Capabilities: [90] Subsystem: Dell Device 04ad Capabilities: [a0] Power Management version 2 00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 04) (prog-if 20 [EHCI]) Subsystem: Dell Device 04ad Flags: bus master, medium devsel, latency 0, IRQ 17 Memory at eeb50000 (32-bit, non-prefetchable) [size=1K] Capabilities: [50] Power Management version 2 Capabilities: [58] Debug port: BAR=1 offset=00a0 Capabilities: [98] PCI Advanced Features Kernel driver in use: ehci_hcd 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a4) (prog-if 01 [Subtractive decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=05, subordinate=05, sec-latency=0 Capabilities: [50] Subsystem: Dell Device 04ad 00:1f.0 ISA bridge: Intel Corporation Q65 Express Chipset Family LPC Controller (rev 04) Subsystem: Dell Device 04ad Flags: bus master, medium devsel, latency 0 Capabilities: [e0] Vendor Specific Information <?> Kernel modules: iTCO_wdt 00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family SATA AHCI Controller (rev 04) (prog-if 01 [AHCI 1.0]) Subsystem: Dell Device 04ad Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 30 I/O ports at 5090 [size=8] I/O ports at 5080 [size=4] I/O ports at 5070 [size=8] I/O ports at 5060 [size=4] I/O ports at 5020 [size=32] Memory at eeb40000 (32-bit, non-prefetchable) [size=2K] Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [70] Power Management version 3 Capabilities: [a8] SATA HBA <?> Capabilities: [b0] PCI Advanced Features Kernel driver in use: ahci Kernel modules: ahci 00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 04) Subsystem: Dell Device 04ad Flags: medium devsel, IRQ 18 Memory at eeb30000 (64-bit, non-prefetchable) [size=256] I/O ports at 5000 [size=32] Kernel modules: i2c-i801 01:00.0 VGA compatible controller: NVIDIA Corporation Device 104a (rev a1) (prog-if 00 [VGA controller]) Subsystem: Micro-Star International Co., Ltd. Device 809f Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at ed000000 (32-bit, non-prefetchable) [size=16M] Memory at e0000000 (64-bit, prefetchable) [size=128M] Memory at e8000000 (64-bit, prefetchable) [size=32M] I/O ports at 4000 [size=128] Expansion ROM at ee000000 [disabled] [size=512K] 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 <?> Capabilities: [100] Virtual Channel <?> Capabilities: [128] Power Budgeting <?> Capabilities: [600] Vendor Specific Information <?> Kernel driver in use: nouveau Kernel modules: nouveau, nvidiafb 01:00.1 Audio device: NVIDIA Corporation GF119 HDMI Audio Controller (rev a1) Subsystem: Micro-Star International Co., Ltd. Device 809f Flags: bus master, fast devsel, latency 0, IRQ 17 Memory at ee080000 (32-bit, non-prefetchable) [size=16K] Capabilities: [60] Power Management version 3 Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: [78] Express Endpoint, MSI 00 Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel 04:00.0 VGA compatible controller: NVIDIA Corporation Device 104a (rev a1) (prog-if 00 [VGA controller]) Subsystem: Micro-Star International Co., Ltd. Device 809f Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at eb000000 (32-bit, non-prefetchable) [size=16M] Memory at d0000000 (64-bit, prefetchable) [size=128M] Memory at d8000000 (64-bit, prefetchable) [size=32M] I/O ports at 2000 [size=128] Expansion ROM at ec000000 [disabled] [size=512K] 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 <?> Capabilities: [100] Virtual Channel <?> Capabilities: [128] Power Budgeting <?> Capabilities: [600] Vendor Specific Information <?> Kernel driver in use: nouveau Kernel modules: nouveau, nvidiafb 04:00.1 Audio device: NVIDIA Corporation GF119 HDMI Audio Controller (rev a1) Subsystem: Micro-Star International Co., Ltd. Device 809f Flags: bus master, fast devsel, latency 0, IRQ 17 Memory at ec080000 (32-bit, non-prefetchable) [size=16K] Capabilities: [60] Power Management version 3 Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: [78] Express Endpoint, MSI 00 Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel