BTX-esque cooling
Although the BTX spec wasn't designed for Athlon 64 systems, Biostar borrows from the BTX cooling scheme for the iDEQ 330P.
The cube features front-to-back cooling, with the CPU socket located right at the front of the system where it should receive the coolest intake air.
A temperature-controlled 92mm fan is tasked with sucking cool outside air into the system. This intake air is first blown over the system's heat sink, whose cooling fins are lined up to make the most of the airflow.
Interestingly, the cooler has a trio of heat pipes that channel heat to different heights along the cooling fin array. These pipes will probably obstruct airflow a little, but they should spread heat more evenly across the cooling fins.
Speaking of the cooler, the 330P's heat sink retention bracket is my new favorite for small form factor systems. A simple lever holds the cooler in place, and it's much quicker to use than Shuttle's new four-screw heat sink.
Once air passes through the CPU cooler, it flows over the system's passive chipset heat sink. NVIDIA's nForce4 chips are notorious for running hot. They usually require active cooling, but there's enough airflow in the iDEQ's wind tunnel to keep the chip cool.
After flowing over the chipset cooler, air is sucked into a temperature-controlled blower and exhausted from the system. The blower and clear plastic shroud that surround the iDEQ's wind tunnel differ from more open BTX designs, and that may not be a good thing. While the shroud does a good job of directing airflow from the CPU cooler to the exhaust blower, the shrouded airflow also isolates the rest of the system. Without other active system cooling elements, the rest of the iDEQ must rely on convection through its vented side panels.
As it turns out, convection isn't enough for some graphics cards. Although the iDEQ was perfectly happy looping 3DMark05 with all its settings maxed on a GeForce 6600 GT, the system would crash within 10 minutes with a GeForce 6800 GT. Removing the case's side panels resolved the stability problems and allowed the 6800 GT to run under load for hours on end, suggesting that overheating was the culprit. We also threw in an ATI Radeon X800 XL 512MB to see what would happen, and to our surprise, it consistently crashed in 3DMark05 regardless of whether the system's side panels were in place.
