Temperatures & overclocking
Temperature musings
We perform our testing on an open test-bed with a 120mm fan simulating case airflow.
| Graphics cards | HIS HD 4850 IceQ4 TurboX 512MB | Sapphire HD 4850 TOXIC 512MB | PowerColor HD 4850 512MB | Force3D HD 4870 512MB | eVGA GTX 260 FTW 896MB | Leadtek 9800 GTX+ 512MB | Inno3D 9800 GT iChill 512MB |
|---|---|---|---|---|---|---|---|
| Ambient temperature | 22°C | 22°C | 25°C | 23.5°C | 23°C | 23.5°C | 24°C |
| Idle temperature | 46°C | 41°C | 77°C | 78°C | 53°C | 53°C | 48°C |
| Load temperature | 58°C | 65°C | 82°C | 90°C | 71°C | 67°C | 61°C |
| Ambient-to-load delta | 36°C | 43°C | 57°C | 67°C | 48°C | 44°C | 37°C |
The reference Radeon HD 4800 series coolers make the cards run
incredibly toasty compared to its NVIDIA rivals, with this reviewer
having scorched his fingers several times whilst removing HD 4850 cards
following testing.
The uprated coolers found on the HIS HD 4850 IceQ4 TurboX and Sapphire HD 4850 TOXIC fare far better, bringing the temperatures to far more acceptable levels whilst maintaining quiet operation. The HIS HD 4850 IceQ4 TurboX maintains the lowest ambient-to-load delta of any of the tested cards, proving the cooler to be very effective.
Overclocking
With the tremendous cooling improvements over the reference design, we would imagine the overclocking potential to also increase.
As such, the speeds were raised the clockspeeds of the HIS HD 4850 IceQ4 TurboX to a maximum stable overclock of 700MHz core and 2,400 MHz memory - a nice boost over pre-overclocked settings.
Looking back at the ET:QW test at 1,920x1,200 we see that HIS HD 4850 IceQ4 TurboX card, at its shipping clocks, scored an average 60.43fps. When overclocked this rose to 63.6 fps: just over a five-percent increase. While this, as an essentially free performance improvement, is not to be scoffed at, we would have hoped for a little more headroom.
