As a note, the final two tests were not executed with the HD4770 overclocked.
Thermal testing involved monitoring the GPU temperature by running GPU-Z with logging enabled. The idle condition was established by recording the temperature after letting the system sit at the Windows desktop for at least 30 minutes with only GPU-Z running. The load condition was established by running 3DMark Vantage two times back-to-back, followed by two back-to-back sessions of the DirectX 9 version of the Devil May Cry benchmark. GPU-Z is capable of logging current, minimum, and maximum temperature, so once all testing was completed, the maximum temperature was recorded. All testing was completed on an open testbed with relatively still air in a room with an ambient temperature of 21C.
While the HD4770 was not the coolest at idle, it was while under a load. Overall, all of the cards performed well in this test, as each has a specially designed cooler intended to keep things from getting too hot.
Power Consumption Testing:
For power consumption testing, a Seasonic Power Angel device was used to monitor the AC wattage drawn by the test system with each video card installed. Since all other hardware remained the same, any change in the Wattage would be the result of the graphics card's demands. Idle conditions were established by letting the system sit at the Windows desktop until a stable reading was achieved, and for load testing the DirectX 9 version of the Devil May Cry benchmark was executed. Peak values were recorded from the Power Angel's display and recorded in the chart below.
With the price and performance of the HD4770 being quite similar to the HD4850 and 9800 GTX+ in many tests, I was hoping to see something interesting when it came to power consumption in order to set it apart. At idle it draws about as much power as the HD4850 and the 9800 GTX+, but under a load it draws 24-44W less. That is rather impressive, and definitely scores a few points for the HD4770!