Power Consumption And Temperatures
In an effort to replicate the way you'd use this PC, we leave power-saving features enabled on both rigs. Also, we don't override the automatic fan controls on either of the stock configurations. As a result, we basically sacrifice thermal performance and impose higher system temperatures in order to enjoy less fan noise.
Both machines employ an Antec VP-450 power supply, which offers respectable efficiency, even if it doesn't boast an 80 PLUS certification.
There's clearly a problem with this quarter's active idle power use on the desktop, since we'd expect it to land right around 50 W. We're thinking that something was messing with the graphics card's power management. And, despite our best efforts, we were unable to solve this mystery.
Monitoring utilities confirmed for us that, at its stock and overclocked settings, the card was properly idling down to its 2D frequencies and voltage levels. Our power meter begs to differ, though. Confirming our suspicion of PowerColor's card is the fact that, when the system enters standby, consumption drops under 42 W instead of giving us the 10-12 W reduction expected from ZeroCore kicking in. For one reason or another, our graphics card simply chews up an extra 20 W on the Windows desktop.
Though the performance of Intel's bundled heat sinks and fans isn't particularly impressive, they serve up quiet operation and adequate cooling, particularly since we're unable to overclock.
At a 20-25% fan duty cycle, our Radeon HD 7850 runs hotter than last quarter's GeForce GTX 560. It's entirely possible that the higher temps are directly attributable to the power consumption issues mentioned above. But GPU load temperatures weren't a big problem. Both overvolted and overclocked cards had cooling in reserve. The Radeon barely hit a 50% duty cycle, while the GeForce peaked at 53%.