Testing (continued):
Thermal Testing:
With performance testing out of the way, the next step was to monitor the GPU temperature while at idle and under a heavy load.
HWMonitor 1.08 was used to monitor GPU temperatures with the cards running on a test platform (no case) in a room with a constant 20C air temperature. The system was allowed to idle at the Windows desktop for at least one hour before the idle temperature was recorded, and then 3DMark06 was executed so that it conducted each test three times before exiting. At this point the maximum temperature reported by HWMonitor was recorded.
Here is where the
Sapphire Toxic Radeon HD3870 and its Vapor-X cooling really stands out. The maximum temperature achieved was 16C less than the comparable ASUS card. Sure, the GPUs are running at different speeds, but even with the Sapphire card overclocked to run at about the same speed, the temperature differential was still 12C! I honestly didn't believe the results at first and repeated testing on the Sapphire card to see 61C was still the maximum.
The cooler on the Sapphire card not only keeps the GPU way cooler, but it also produces less noise at full speed. The ASUS card ramps up and down more often, and when it is cranked all they way up it is louder than the Sapphire card.
Power Consumption Testing:
Monitoring the power consumed by the system with each card installed was the final test. A
Seasonic Power Angel was connected to the power supply in order to monitor the Wattage drawn from the power outlet. The idle power consumption reading was recorded with the system at the Windows desktop and nothing else running. 3DMark06 was then executed and the Power Angel was monitored in order to identify the maximum value achieved.
Comparing the values above shows that there is no significant difference between the cards. At idle the system with the Sapphire card installed drew a couple Watts more, but at full load it drew a few Watts less. Over the course of a typical day, the rise and fall on each card would probably average out to about the same value.
