My motherboard (an Intel WG965DH) doesn't support DVI out natively. An ADD2 card plugged into the PCI-Ex16 slot solved that quickly and cheaply.
lspci -vv output:
00:02.0 VGA compatible controller: Intel Corporation 82G965 Integrated Graphics Controller (rev 02) (prog-if 00 [VGA controller]) Subsystem: Intel Corporation Unknown device 514d Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Interrupt: pin A routed to IRQ 16 Region 0: Memory at e0300000 (32-bit, non-prefetchable) [size=1M] Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M] Region 4: I/O ports at 3410 [size=8] Capabilities: [90] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable- Address: 00000000 Data: 0000 Capabilities: [d0] Power Management version 2 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 PME-Enable- DSel=0 DScale=0 PME- 00:02.1 Display controller: Intel Corporation 82G965 Integrated Graphics Controller (rev 02) Subsystem: Intel Corporation Unknown device 514d Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 0 Region 0: Memory at e0200000 (32-bit, non-prefetchable) [size=1M] Capabilities: [d0] Power Management version 2 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 PME-Enable- DSel=0 DScale=0 PME-