Thermal Performance

We've changed our thermal testing procedures to one that we feel more accurately represents real world gaming. When you're in a gaming session there are peaks and troughs in demands that are put on your GPU. These can be in the form of you dying and getting a loading screen, messing around in the menu system or simply travelling around part of a map where there aren't any explosions of other pwnage to render. During these stages, your graphics card cooler will dissipate excessive heat that was built up during more graphically intense periods of game play.

Synthetic benchmarks such as FurMark thrash the GPU constantly. Not only is this not reflective of how a GPU will be getting abused in gaming, it's such a hardcore test that any GPU under test is almost guaranteed to hit its thermal limit, the mark at which the card's firmware will kick, speeding up the fan to keep the GPU withib safe temperature limits. For this reason, we were getting results that were more dictated by the cards' firmware than the cooler, as no matter how good the cooler was, FurMark was going to keep pushing until the GPU was hotter freshly microwaved do-nut jam.

Instead, we now load up a level of Crysis in DirectX10 mode at 1,920 x 1,200 with 4x AA and leave it as it stands, resisting the urge to jump on and start playing. Every time the character is killed, the game loads again automatically from the last save point and the cycle is repeated. This process more accurately replicates the peaks and troughs of a gaming session. We leave it for an hour until the temperature has stabilised and then compare the delta Ts.



We've seen from previous reviews that the Vapor-X cooler does its job well and that's the case again here. Something we spotted with the Sapphire compared to a stock HD 4890 is that the latter was actually cooler at idle and under load. However the reason for this is that the stock card is much louder and easily the nosiest bit of hardware in our tests system. The noise of Sapphire's Vapor-X cooler, on the other hand, wasn't noticable above the other hardware even during games. Reducing the stock cooler fan speed to get similar noise levels would almost certainly result in instability so all credit goes to Sapphire.

We decided on an additional test in our regular thermal benchmarks. As well as including a stock HD 4890, we also increased the fan speed on the Sapphire Radeon HD 4890 Vapor-X 2GB to similar levels to that of the stock card (about 70% fan speed). This is only to approximate noise levels but it should give an idea of how efficient the Vapor-X cooler is compared to the stock cooler at similar noise levels.

The green bar shows how the Sapphire performed at 70% fan speed - clearly the Vapor-X cooler is much more efficient than the stock cooler managing to knock 7°C off the load temperature and 6°C off the idle temperature. This is particularly impressive seeing as Vapor-X cooler is dealing with an overclocked card as well. If you don't mind the noise, the Vapor-X cooler can knock spots off the stock cooler but more importantly deal out similar temperatures at much lower noise levels. It's not water-cooling quiet but it will probably mean your graphics card is no longer the noisiest component in your PC.