Temperatures and overclocking
Temperature musings
We perform our testing on an open test bed with a 120mm fan simulating case airflow.
| Graphics cards | Force3D Radeon HD 4870 512MiB | Sapphire Radeon HD 4870 512MiB | Sapphire TOXIC Radeon HD 4850 512MiB | Sapphire Radeon HD 4850 512MiB | XFX GeForce GTX 260 896MiB | NVIDIA GeForce 9800 GTX+ 512MiB | BFG GeForce 9800 GTX 512MiB |
|---|---|---|---|---|---|---|---|
| Ambient temperature | 23.5°C | 25°C | 22°C | 21°C | 24°C | 23.5°C | 21.5°C |
| Idle temperature | 78°C | 71°C | 41°C | 71°C | 48°C | 53°C | 52.5°C |
| Load temperature | 90°C | 83°C | 65°C | 81°C | 72°C | 67°C | 67°C |
| Ambient-to-load delta | 66.5°C | 58°C | 43°C | 60°C | 48°C | 44°C | 45.5°C |
With a 90°C load temperature, clearly the reference cooler running at its low fan-speed setting is something of a drawback. We're still hoping ATI and its partners can fix this through a BIOS or driver update, but at present, an after-market cooler would certainly look tempting.
Overclocking
Despite the poor cooling, we were able to overclock the core and shaders to a fully stable 810MHz, and memory to a blistering 4,400MHz - yup, 4.4GHz/s With better cooling we're sure you could push even farther.Looking back at the ET:QW test at 1,920x1,200 we see that the stock-clocked card scored an average 69.83fps. When overclocked this rose to 75.07fps (a 7.5 percent increase). Certainly nothing to sniff at.
