To test the temperatures of the Sapphire Vapor X 5750 I fired up FurMark 1.70 and GPUz. Running FurMark at a resolution of 1024x768 was more than enough to bring the work load to 100%
All temperatures were taken with the fan control on auto. Starting out at 48 degrees is comparable to what the reference 5750 started out at. Under full load however, is a different story. The reference card jumped up to 74 degrees while the Sapphire Vapor-X HD5750 held steady at 63 degrees, a difference of 11 degrees. You can find the details on the reference card here.
Benchmark results: The Vapor X cooler keeps the Sapphire Vapor X 5750 at a comfortable temperature of 63 degrees Celsius.