Overclocking, Temperatures, and Power Consumption
When it comes to overclocking the R9 285… well… the results speak for themselves. Unfortunately this particular card is voltage locked, meaning that whatever voltage this card is saddled with when you get it is the voltage you get, regardless of willingness to overclock further than the BIOS-imposed limit of 1150 MHz on this card. Still, the ability of this card to effortlessly hit 1140 MHz on the core and 1500 MHz memory is pretty nuts. I was able to do a little bit of testing with the core pegged at 1150 MHz, but I wound up encountering persistent artifacts and game crashes that forced me to back off 10 MHz. An extremely healthy overclock by any standards!
For the sake of checking out what kind of performance gains you get overclocked, I re-ran some of the quicker benchmarks just to see what kind of gains you should expect. In total, the overclock produced repeatably good results and definitely reinforces the strong value and capabilities present with this Tonga core.
The heat sink for this card is nothing short of brilliant, if not entirely unassuming. After allowing the Unigine Valley test to loop for several hours, I discovered that the card simply refused to climb over 76 C, and that was overclocked! It also managed to do this while maintaining a reasonable tone with the fans; they were noticeable, but not irritatingly so, which is awesome if you are like me and happen to be OCD about how quiet your PC is.
System Power Consumption: New School v Old School
For power consumption I chose to test a friend’s 7950 he had. I set the 7950 to the same clock speed as the R9 285 we had on hand today to give both cards as sporting a chance as possible to see how much better power consumption has gotten from generation-to-generation. My measurements were done in Watts using a Kill-A-Watt meter, and as expected the R9 285 is more energy efficient at all states, but the real difference occurs when the cards are under load with OCCT’s Power Supply test to load the entire system. These are nice gains considering that the underlying architecture still shares its roots with the 7950-based architecture it replaces, and showcases AMD’s increasing mastery over their current manufacturing node.
So now that we have a complete picture, let’s wrap this up.