If you need to pack a whole lot of PCs into a small space, you’ll likely turn to rack mount servers. Rack mount computers can be found everywhere from the world of video editing suites and 3D render farms, through installations at ISPs, telecoms, and database houses. As their name implies, rack mount servers are designed to fit into an open computer rack or closed cabinet. Their space-saving design allow for the maximization of available square-footage.

And just as important, placing all of the equipment into a specially designed housing makes it easier to attain both climate control and cable management.

While the racks are available in a wide variety of heights and configurations, rack mount servers come in seven specific sizes–1U, 2U, 3U, 4U, 5U, 6U, and 7U–as defined by the Electronic Industries Association (EIA). The numbers describe the height of the server case. The smaller the number, the shorter the server. The width is a constant at 19 inches.

It took a while to find an exact definition of server height.

After much searching, I hit pay dirt at RackmountEnclosures.com, where 1 Rack Unit (RU) is defined as 1.75 inches. Following that, a 1U server measures in at 1.75 inches, a 2U at 3.5 inches, 3U at 5.25 inches, a 4U at 7 inches, and so on. So how much computer can you stuff into that space? RackmountEnclosures boasts that their RC0424 unit is the first 4U server on the market to accomodate a whopping 24 hard drives. All that, and hot swappable, too!

While rack mount servers are a staple of the high-tech business world, they’re rarely found in the household, save for those households of the highly geeky. I’ve long thought that the day of the household rack mount server is near. Why shouldn’t our mega-jukeboxes, ultra-DVRs, and monster home financial number crushers be placed in a nice safe quiet closet somewhere … behind neon-lit glass, of course … so we can geek out for the neighbors … :)