The SV231QDVIUA 2-Port Quad Monitor Dual-Link DVI USB KVM Switch allows 2 PCs, each with 4 DVI video outputs, to share monitors, 1 microphone and set of speakers, 1 keyboard and 1 mouse as well as an additional USB 2.0 peripheral such as an external hard drive, thumb drive, printer, or webcam. The Quad DVI KVM switch allows you to switch back and forth between 2 multi DVI PCs at the touch of a button, while maintaining professional-level video quality on all monitors at resolutions up to 2560x1600. The quad DVI switch also features an integrated USB hub port that allows USB 2.0 peripherals to be shared between attached systems - eliminating duplicate peripheral costs, and offering the convenience of sharing stored data between PCs. Backed by a StarTech.com 3-year warranty and free lifetime technical support. PLEASE NOTE: While both DVI-I (analog mode) and DVI-D (digital only) are supported by the KVM, both source PCs must output the same signal type for proper switching. It is recommended wherever possible to use DVI-D cables across all PC to KVM and KVM to Console connections.Please contact technical support for assistance identifying your source.