Cooling Efficiency Tests
Radeon HD 4890
Before we move on to the main diagram with the test results, let’s compare the efficiency of Thermalright T-Rad2 GTX with one 120 mm fan and with two 92 mm fans. Two 92 mm fans have already been discussed in our today’s article, and as for the 120 mm fan, we picked a pretty quiet Noiseblocker NB-BlackSilent XL2, which rotation speed was set at 1380 RPM with the help of the controller. In terms of generated noise, this mode is only a little louder than with two 92 mm Thermalright fans at 1530 RPM. Let’s take a look at FurMark results:
In my opinion, the results are quite predictable and logical. Two 92 mm fans not only cover a larger area than one 120 mm fan, but also have higher static pressure, which is important for T-Rad2 GTX with its dense heatsink array. The advantage of a dual-fan configuration is obvious.
Another thing that I would like to dwell on is the difference in VRM temperatures with VRM1 and VRM2 heatsinks. In our case, VRM2 proved to be more efficient, because its heatsink was parallel to the fan of the tower CPU cooler that I used. However, as you probably understand, this is not a rule, but mostly a specific situation. It is much more interesting to find out how the temperatures will differ when we use a passive VRM heatsink and a VRM heatsink with an 80 mm fan on it. For that purpose we used an open testbed and tested Radeon HD 4890 with Thermalright T-Rad2 GTX and VRM1 heatsink, which gets much less help from the processor fan than VRM2. Take a look at the photos below and the obtained results:
The results of our tests showed that VRM1 heatsink with an 80 mm fan cools the graphics card voltage regulator components 6-7 °C better than in passive mode. I can’t say that it is a serious difference, especially since the critical temperature of Radeon HD 4870/4890 VRM components is around 130 °C. However, it is present. Here I have to add that when we top the VRM1 heatsink with a fan, it will be very close to the system case side panel (less than 1 cm away in Antec Twelve Hundred case).
So, here is the diagram with the coolers results on Radeon HD 4890:
The only mode where we can compare the results of our main hero against those of the reference Radeon HD 4890 cooler is the moderate noise mode, and even that at a certain stretch. Both, Arctic Cooling Accelero Twin Turbo and especially Thermalright T-Rad2 GTX work at maximum fan rotation speed much quieter than the stock Radeon HD 4890 cooler at medium fan speed. And as you can see, T-Rad2 GTX wins a convincing victory not only over the stock HD 4890 cooler, but also over Accelero Twin Turbo. Note that T-Rad2 GTX working in quiet fan mode at only 980 RPM cools the graphics card 5-8 °C better than Accelero Twin Turbo at its maximum fan rotation speed. It is an excellent result! T-Rad2 GTX’s advantage over the stock HD 4890 cooler reaches as high as 40 °C. Here you should keep in mind that the VRM2 heatsink for the graphics card voltage regulator components helps a lot (in fanless mode, by the way). Without it VRM temperatures hit beyond 120 °C with both: T-Rad2 GTX, as well as Accelero Twin Turbo.