Something I didn’t know about KVM switches and Motherboard BIOS…

Ville Walveranta — Wed, 02 Sep 2009 19:31:06 +0000

I recently installed Gigabyte GA-EP45T-UD3LR motherboard to a small LAN file server. It’s a decent, stable, inexpensive board. But what I didn’t realize is that if you want to use a shared USB keyboard and mouse with a Windows system, some BIOS options must be available and editable (assuming they’re not set “correctly” by default from the KVM switch’s point of view). This motherboard’s BIOS doesn’t have those options and apparently the BIOS defaults aren’t the right ones for this kind of use. The result: once USB keyboard and mouse have been switched away from the system with a KVM switch, they’ll never be reacquired by the system until the system is rebooted. Fortunately RDC works so that the console is not usually—or at least is very rarely—needed…

For reference, if you’re planning to use a Windows system with a KVM switch, make sure its BIOS has the following options:

HALT ON ERROR: All but keyboard (usually in Standard CMOS settings)
PnP OS: yes (usually in PnP/PCI settings)
USB IRQ: enabled (usually in PnP/PCI settings)

Without these options set the only way to find out whether a specific motherboard will or will not work with a USB KVM switch, is to try. Gigabyte GA-EP45T-UD3LR does not.

My Galagzee! » gigabyte

Something I didn’t know about KVM switches and Motherboard BIOS…