Thermal Performance

We've changed our thermal testing procedures to one that we feel more accurately represents real world gaming. When your in a gaming session there are peaks and troughs in demands that are put on your GPU. These can be in the form of 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 any excessive heat that was built up during more graphically 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 it's 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.


The huge Accelero Xtreme Arctic Cooling cooler has an huge influence on the iChill GTX 275's core temperatures thanks to it's large cooling array mounted to the card's 55nm GT200 core. Idle temperatures drop by a full 12°C are an impressive feat considering GT200b based card's already have a very capable low-power mode that significantly lowers operating temperatures when idle. That said, the low power idle mode is directly linked to a very low fan speed turning down the noise, where the iChill doesn't favour such a delicate approach to fan control.


Load temperatures are even more impressive, with the massive aftermarket cooler dropping the card's core operating temps by a massive 31°C during intensive Crysis gameplay. While this heat is instead exhausted into the case rather than out the rear as it is with a stock card, a well ventilated chassis like the Antec 1200s we use for testing, negate this issue and allows the iChill to operate to it's full cooling potential. What's perhaps even more impressive is that the three 92mm fans are surprisingly quiet, and while not silent, are still audibly stealthier than a stock GTX 275's paddle fan buzzing away at an elevated frequency.