The following screenshots sum up the characteristics of the new reference cards from AMD:
Each card sports a new dual-slot cooler that consists of a massive heatsink with evaporation chamber and slim aluminum fins, a metallic base, a blower, and a plastic casing on top of all that.
By the way, you can remove the casing by undoing the side locks, without taking the whole cooler off the card.
The evaporation chamber lies over the whole heatsink surface.
The chamber has no contact with the memory chips which are cooled by a metallic plate in the base of the cooling system. There are thermal pads in between.
Gray-colored thermal grease is used for the GPU.
The cooling systems are equipped with 80mm fans from Foxconn, PVB070G12N model. Unusually for graphics cards, the fan has a power rating of 24 watts.
The speed of the fan is regulated automatically by means of pulse-width modulation within 1200 to 5800 RPM interval. We can remind you that the top fan speed of the Radeon HD 58xx and 68xx series cards is no higher than 5000 RPM (and usually no higher than 4500 RPM), so we suspect that the new Radeons won’t be quieter than their predecessors. Let’s check this out right now.
To perform our temperature tests we installed each card into a closed system case which configuration is listed in the next part of the review. The ambient temperature was 25°C. As a typical load the system ran Aliens vs. Predator (2010) at 1920x1080 with 16x anisotropic filtering. As a high load we launched FurMark 1.8.2 from a renamed exe-file in Xtreme Burning Mode (at 2560x1600 and with 16x anisotropic filtering forced on in the Catalyst and GeForce/ION drivers). We used GPU-Z 0.4.9 and MSI Afterburner 2.1.0 beta 5 for monitoring.
First let’s see how hot the cards are under typical gaming load in the automatic fan control mode.
As far as Radeon HD 6950 graphics card is concerned, its thermal and acoustic performance are within acceptable limits, since the GPU only warmed up to 81°C and the cooling fan only sped up to 2260 RPM. At this point you can hear the fan working, but the overall noise from the graphics card remained with the acoustic comfort zone. As the number of runs in the gaming test increased, the temperature remained the same. Note that Aliens vs. Predator (2010) is one of the heaviest games in respect to graphics card thermal conditions.
Before we get to analyze the thermal readings taken off the Radeon HD 6970 graphics card, we have to say the following. The thing is that the AMD Radeon HD 6970 graphics card sample we received was not quite operational right from the start. It could work stably only in 2D mode, and as soon as we launched any 3D application, the fan rotation speed started jumping and so did the GPU temperature. We assumed that it was that notorious thermal throttling kicking in, therefore we changed the rotation speed adjustment limit to the maximum of +20%, but it didn’t amend the situation. So, assuming that the graphics card GPU was simply getting overheated, we removed the cooler and replaced the default dried out thermal interface with Arctic Cooling MX4. Only after this minor modification that graphics card started working stably in 3D applications. However, its thermal readings as well as the generated noise left much to be desired. For example, the GPU temperature rose as high as 104°C and the fan sped up to 4760 RPM! Of course, there is no comfort of any kind in this case. Luckily, Aliens vs. Predator (2010) turned out to be the only test in our list that heated up the graphics card so badly. However, we still tend to believe that the AMD Radeon HD 6970 sample we received wasn’t quite alright after all.
Nevertheless, we decided not to give up graphics card tests in FurMark, and here are the obtained results when the fans were working in automatic rotation speed mode:
And these are the results at maximum fan rotation speeds:
One more time we can hardly complain about the results obtained on Radeon HD 6950: 90 degrees C at only 2800 RPM in auto mode and 71°C at the maximum speed of 5770 RPM. As for Radeon HD 6970, it failed the FurMark test at maximum fan rotation speed and had to force the GPU frequency down to 500 MHz to complete.
Because of these shocking results shown by Radeon HD 6970 during our temperature tests and the absence of any alternative cooling solutions at the time (primarily because of the absence of VRM heatsinks), we decided to overclock only the Radeon HD 6950. Here is what we got:
The GPU frequency potential turned out pretty modest, since we managed to increase the clock speed by only 70 MHz (+8.8%), while the graphics memory really did well and hit the impressive 5880 MHz of effective frequency. I have to point out that even after overclocking the graphics card temperatures remained the same. In fact, it remained exactly the same. Only the fan started to work at 100-150 RPM higher speed depending on the type of load.