Cold as ICE
Like the rest of Shuttle's recent XPC systems, the ST61G4 uses an elegant ICE cooler to keep temperatures under control.

Too pretty to be cooped up in a cube, don't you think?

The L-shaped ICE cooler is built on a copper base and uses an array of cooling fins and heat pipes to channel heat away from the system's processor.

Shuttle's simple and effective heat sink retention clip

Shuttle anchors the ICE cooler with a slick little retention clip that's remarkably easy to work with around the cramped CPU socket.

Sunon provides fans for the ICE cooling system

No rubber dampers

Shuttle has used the same 80mm Sunon in its last several XPC systems, and for good reason. When combined with the ST61G4's BIOS, which can manipulate fan speeds based on processor temperatures, the fan oscillates between being reasonably quiet and nearly silent. Shuttle claims that the ST61G4 is the quietest cube it's ever built, and I'm inclined to agree.

Unfortunately, I can't help but wonder if the ST61G4 couldn't be made even quieter with the selective use of rubber bumpers to dampen vibration. Shuttle's recent SB75G2 uses rubber bumpers around the exhaust fan's mounting cage, but oddly, the newer ST61G4 doesn't.

Since the cost of rubber bumpers has to be somewhere in the neighborhood of negligible, it's puzzling that they aren't used on the ST61G4, especially since Shuttle appears to be pushing the cube as a near-silent system. I'd actually like to see Shuttle use rubber bumpers on more than just the exhaust fan mount; the cube's internal drive cage could use a bumper or two to help dampen vibrations from spinning disk drives.