The blower has not changed, either. It is the CF1275-B30H-C004 model from NTK Technologies Inc.

Besides checking the efficiency of the Radeon HD 4890’s cooler, I will compare it with the reference Radeon HD 4870 that has the following specs:

The Radeon HD 4890 is represented by the reference card from HIS. First let’s see what temperatures the cards have at the default frequencies and in the automatic fan control mode. 

Notwithstanding the higher frequencies, the Radeon HD 4890 is cooler than the Radeon HD 4870 but you should note that the HD 4890’s fan worked at 2800rpm whereas the HD 4870’s at 2200rpm only. Next, let’s see what temperatures the cards have at the maximum speed of their fans:

Now the Radeon HD 4870 is cooler, just as you can expect. The difference in the previous test must have been due to the difference in the fan speeds. The overclocked Diamond is just as hot as the HIS card under load but its fan is rotating 240-300rpm faster.

To compare the reference Radeon HD 4890 cooler with an alternative, I took one of the best options in this class – an Arctic Cooler Accelero Twin Turbo. I installed it on the GPU while the power components and the memory chips were cooled by the plate from the reference cooler.

My attempt failed, however, Even at the max speed of the Twin Turbo fans the card got alarmingly hot 3 minutes into FurMark and I had to stop the test.

Therefore I checked the cards’ overclockability with the reference cooler working at its max speed. Alas, the HIS card could only be accelerated to 910/4400MHz. The pre-overclocked card from Diamond did not show a good result, either. 

The memory frequency of the overclocked HIS is good but its GPU is a disappointment. There was no talking about 1000MHz with that sample. I hope you’ll be luckier with yours. If you don’t want to rely on luck, you may want to consider the HIS Radeon HD 4890 TURBO 1GB that has default frequencies of 900/4000MHz. The GPU of the Diamond card could not be overclocked at all while its memory worked at 4560MHz.

The Radeon HD 4890 has a recommended price of $249. You can email me for the BIOSes of the two described models.