Is there an obvious reason that they stick with traditional air cooling for this, rather than using liquid cooling? Here's an example of a compact system with liquid cooled CPU and graphics card built using off-the-shelf parts: http://blog.newegg.com/building-a-mini-itx-gaming-pc/
I'd think that at this small size, you'd need really high air velocity to make it work. Coupled with small fans, this generally means the system would be really noisy. Is liquid cooling still too expensive? Not reliable enough? Not actually an advantage for noise? Or do the expected purchasers just not care about excessive fan noise?
Duh. OP suggests liquid cooling would give some benefit to acoustic performance.
Really, it just adds complexity and bulk; it's not some magic solution to efficiency or increased performance. Especially in a compact form factor.
If volume is not a constraint, sure the availability of added surface area to dissipate the heat collected from a smaller surface area is beneficial. Most high performance, low resonance liquid cooling systems take advantage of increased surface area using oversized radiators and multiple low-speed fans.
I have successfully designed and implemented my own custom water cooling loops to pull concentrated heat from multiple components, but there is most definitely no benefit to the volume occupied by the entire system.
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,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.
The supported E3-1270, 1275, and 1280 are rated at 80W. I'm not sure about the M620 GPU, but since it's the successor to the 45W K620, that might be a good guess. If they need to offer the 200W version, I assume they will occasionally need to handle at least 135W of cooling inside the chassis.
I'd think that at this small size, you'd need really high air velocity to make it work. Coupled with small fans, this generally means the system would be really noisy. Is liquid cooling still too expensive? Not reliable enough? Not actually an advantage for noise? Or do the expected purchasers just not care about excessive fan noise?