Desktop KVM units that enable you to switch a mouse, keyboard and display between a number of PCs have been around for years, but most use the old VGA display port and PS2 peripheral connectors.

Avocent's four-port Switchview DVI is suitable for newer PCs that use a DVI display port and USB2 instead of PS2 peripherals.

It can also switch a mic and speaker between PCs and it packs a switchable two-port USB2 hub.

By default all peripherals switch at the same time when you press specified hotkeys or one of four buttons on the front of the device; other hotkeys enable you to lock the audio and/or the hub to a particular PC. They take a little figuring out as the multi-language instruction sheet is not at all clear.

Setting up the hardware is fairly simple. You plug the keyboard, mouse, display, and audio leads into the peripheral ports, and cables are provided to link PCs to the four switched ports.

The supplied cables are DVI-i , which means the connectors include four analogue pins. Our Dell monitor, like many current models, uses a VGA port for analogue signals and its DVI-d digital port would not take the supplied DVI-i plug.

This would not normally be a problem as most similar monitors will come with a DVD-d cable that can be used with the Switchview, but it is confusion users could do without.

It is also avoidable, because it turns out that the Switchview does not support the analogue pins – something we discovered only by checking with Avocent.

Full DVI-i support would enable the device to switch both analogue (with a VGA-to-DVI-i adaptor) and digital signals to the same monitor, provided you could find one that supported DVI-i.

When we first set the Switchview up, it switched the display but the mouse and keyboard functioned on only one port. This was probably due to the fact that we hot-swapped leads into machines that had been using PS2 rather than USB devices, and the PCs took time to load the right drivers. It soon began switching okay.

As a final test we plugged a USB flash drive into the Switchview's two-port hub and switched it between an XP and Vista machine. We expected trouble and we got it.

Both machines mounted the drive when it was switched to them, but when we switched back both reported that it was malfunctioning, though there was nothing wrong with it.

Switching a drive in this way is, of course, equivalent to unplugging it without dismounting it properly and could result in the loss or corruption of data.

Avocent should not assume that users know this and should have included a warning in the documentation. You can happily use the hub with a USB drive if it is locked to one PC.

These caveats aside, this device is a good choice if you wish to switch between PCs equipped with DVI graphics cards.