Power consumption
Next up on our testing schedule let's spend some time taking a look at power consumption. Rather than isolate the power consumption of the individual component being reviewed, we'll instead be taking a look at the power consumption of our test system as a whole to get a more real-world example of how an average system will behave in this discipline.
For this review, we've split our power consumption testing into three segments, measuring the power used first when idling at a Windows 7 desktop, followed by testing again while playing back a Blu-Ray movie and then running an intensive 3D rendering task courtesy of 3DMark Vantage's two GPU tests.
Despite their clock speed differences, there's no real discernible changes in power consumption between XFX and Sapphire's Radeon HD 5770 boards, even under a full 3D rendering workload - Both cards retain the same overall power profile which sees our system consume a little over 130 Watts at idle and 210 Watts under load.
GPU temperature
Let's now take a look at GPU temperatures using these parts, to see how these two Radeon HD 5770 graphics boards and their differing cooling solutions handle any heat generated by its Cypress core. We'll be examining GPU temperatures first after idling at a Windows 7 desktop for a few minutes, and then again after thirty minutes under load via looping 3DMark06's 3D game tests.
In all fairness to AMD's reference dual-slot cooling solution, it actually does a very good job when it comes to its primary purpose (that is, cooling), the evidence of which comes from it posting the lowest load temperatures of our three solutions here. Needless to say, the higher clock speeds of XFX's Radeon HD 5770 XXX negatively affect this board's GPU temperatures using that same cooler, making it the hottest of the three cards (but never dangerously so).
In contrast, Sapphire's Radeon HD 5770 Vapor-X really makes the most of its vapour chamber cooler at idle, reducing temperatures compared to the reference design by around seven degrees compare to XFX's offering. At load it posts broadly similar GPU readings to AMD's own cooler, which leaves us with more than acceptable load temperatures, although of course once again we have to point out that the Radeon HD 5770 Vapor-X doesn't have the advantage of dumping that warm air outside of the chassis. Overall though, the Vapor-X solution is definitely onto a winner here, although you won't suffer from overly high temperatures with an AMD reference-based cooler either.
Noise levels
Finally, let's close out this review by taking a look at the noise levels of these two cards and their differing cooling solutions - First at their default idle speed, then again under load with 3DMark Vantage's GPU tests running. For this test, we've measured the overall noise level from inside the system chassis, just under the graphics board's cooling fan, thus making these figures very much a worst-case scenario for the overall noise generated by this part.
This is where Sapphire's Radeon HD 5770 Vapor-X cooler really comes to its own - Quite simply, it's notably quieter than AMD's reference cooler, and if you're putting it in a quiet enough system in the first place chances are you'll be able to notice the difference. Again, this shouldn't be seen as criticism of the default Radeon HD 5770 cooler per se, as it actually performs pretty well in its own right (albeit very slightly noisier when paired with a factory overclocked board such as our XFX offering), but as per usual Sapphire's Vapor-X solution is a cut above what AMD themselves have managed to offer.
