Ex-data centre bod here....from my experience, in the DC&#x27;s I&#x27;ve worked in (in the UK and Europe), the racks used were most often 600mm(w) x 800mm(d) 42U, or 800x800 racks if the rack was densely cabled (i.e. there being a gap on either side of the 19&quot; frame to bring in cable from the sides). These would then sit on 600x600 raised floor tiles, which was a convenient thing, geometry-wise.<p>But that was back in the late 90&#x27;s&#x2F;early 2000&#x27;s, so things might have changed.