With the Phoronix Test Suite, we are also able to monitor the system's hardware sensors while running any test profile. When running Unigine Heaven at 2560 x 1600 for a second time, the Phoronix Test Suite 3.0-Iveland software polled the GPU temperature and other sensors. The average temperature of the Radeon HD 6870 under this Unigine Heaven workload wasn't quite as low as the NVIDIA GeForce GTX 460 or Radeon HD 5750, but of course the Radeon HD 6870 is a much more powerful GPU than those two graphics cards. The GPU temperature for the Sapphire Radeon HD 6870 with its Vapor-X cooler was right on par with the Radeon HD 5770 and its reference cooler. Unfortunately, due to having access to no other Radeon HD 6870 graphics cards we cannot compare the Vapor-X cooler directly, but with the average temperature under extreme load being under 60C for the Radeon HD 6870 and idling at under 40C, the cooler is more than sufficient.
While the average fan speed (as a percent) is not too relevant in comparison, even under the Heaven workload the fan speed for the Radeon HD 6870 was never maxed. Under the workload, it was running at around 50% its maximum speed, according to the data obtained by the Phoronix Test Suite when utilizing AMD's OverDrive extension. The fan speed when starting out from idling was around 30%.
The CPU usage ended up being about the same when running Unigine Heaven although it was slightly higher with NVIDIA's proprietary driver, which is something that we have noticed with previous tests as well.