Power, Cooling, And Overclocking
The onboard component list for Shuttle’s tiny XPC SX58H7 is nearly identical to its larger competitor, so we expected similar power consumption when both systems were returned to factory-default speeds (20x 133 MHz CPU, DDR3-1066) with all power-savings features enabled. However, Asus cheated a little: in an effort to make its system “more overclockable,” it added 0.20 V to the CPU using the Auto voltage setting (even with voltage-boosting Load-Line Calibration disabled). Enabling power-saving modes through the Asus EPU utility dropped the core voltage appropriately, but the software was too poorly designed to respond to Prime95 loads with an increase to full speed. Getting the CPU to stock speed and voltage on the Asus P6T required disabling Asus EPU and manually setting the proper CPU voltage in BIOS.
Even with big-system features shoved into tight confines, the XPC SX58H7 beats Asus in efficiency. P6T users will also find an increase in full-load power consumption of over 20 W when using default performance mode under Asus EPU.
Cooling is the biggest reason performance fanatics typically choose large cases, but overclocking isn’t a primary function of Shuttle Form Factor design. Since compact system buyers must be able to accept near-stock speeds as a tradeoff for small size, the SX58H7 only has to match Intel’s boxed cooler for us to consider its cooling system a complete success. We returned to our earlier 3.20 GHz clock speed to assure both coolers were running near their full capacity.
Graphics card cooling suffered slightly at around three degrees Celsius, while CPU temperatures increased by five degrees Celsius. However, temperatures for both platforms are adequately low, so the SX58H7 cooling and ventilation should be good enough for most buyers.
With cooling of an extra-hot processor moderately successful, it was time to push both platforms to overclocking limits.
We were hoping to reach 3.60 GHz on both systems, but the SX58H7 was only cool enough to support 3,573 MHz. Heat problems prevented us from pushing core voltage on the XPC beyond 1.20 V, while the boxed Intel cooler withstood the 1.275 V needed to reach the P6T’s higher overclock speed.
Neither the XPC nor our Asus-based reference platform are stellar in the area of base-clock overclocking, but Shuttle’s 202 MHz result is still more than enough to reach the system’s maximum CPU speed.
