Absolutely it's smaller. Did you notice that they have designed it so that it can act as a VESA mounting plate that goes between a swing arm and the monitor?

Absolutely it's smaller. Did you notice that they have designed it so that it can act as a VESA mounting plate that goes between a swing arm and the monitor? http://media.bestofmicro.com/B/N/628979/original/HP-Z2-Mini-Mounting.jpg http://media.bestofmicro.com/B/N/628979/original/HP-Z2-Mini-... I wasn't suggesting that mini-ITX was a substitute. It's only compact for something that uses standard hardware. What I was wondering was why they stuck with air cooling despite using a custom form factor. I presume there are reasons for this --- I just don't know them. HP does claim that this machine is "63% quieter than a comparable HP business-class mini PC.": http://www.tomshardware.com/news/hp-z2-mini-g3-workstation,33027.html http://www.tomshardware.com/news/hp-z2-mini-g3-workstation,3.... My previous experience with HP machines though is that I hate being in the same room as one even when it is at idle. So even if this is 1/3 as loud, it may still sound like a vacuum cleaner.