Temps, overclocking, power-draw
Temperature musings
We perform our testing on an open test-bed with a 120mm fan simulating case airflow.
| Graphics cards | Sapphire Radeon HD 4870 X2 2GB | Force3D Radeon HD 4870 512MB | PowerColor HD Radeon 4850 512MB | BFG GTX 280 1GB | EVGA GTX 260 896 MB | BFG GeForce 9800 GTX+ 512MB |
|---|---|---|---|---|---|---|
| Ambient temperature | 24°C |
23.5°C | 25°C | 21.5°C |
23°C | 23.5°C |
| Idle temperature | 73°C |
78°C | 77°C | 47°C | 53°C | 53°C |
| Load temperature | 95°C | 90°C | 82°C | 74°C | 71°C | 67°C |
| Ambient-to-load delta | 71°C | 66.5°C | 57°C | 52.5°C | 48°C | 43.5°C |
Radeon HD 4800-series' idle and load temperatures remain a concern, idling, as they do, significantly higher than the NVIDIA GPUs. We have to wonder just what effect the elevated temps will have on longevity; only time will tell.
Power-draw
| Graphics cards | Sapphire Radeon HD 4870 X2 2GB | Force3D Radeon HD 4870 512MB | PowerColor HD Radeon 4850 512MB | BFG GTX 280 1GB | EVGA GTX 260 896 MB | BFG GeForce 9800 GTX+ 512MB |
|---|---|---|---|---|---|---|
| Idle draw | 149W |
141W | 106W | 107W |
103W | 114W |
| Load draw | 366W |
216W | 175W | 260W | 227W | 194W |
Measuring power-draw at the mains by running 3DMark06's Canyon test at 1,920x1,200 4xAA 16xAF, we see the X2 consume over 100W more than any other card. However, we imagine that the card wil be idle most of the time and, as such, the 149W power-draw is actually pretty good.
Overclocking
AMD chose not to increase the frequecies of the dual-GPU Radeon HD 4870 X2 when compared with the regular card - a move away from the HD 3870 X2.
We managed to raise default clocks (750/750/3,600MHz) to 775/775/3,826MHz comfortably enough, and it added 2.5 per cent to the average framerate at 1,920x1,200 in Enemy Territory: Quake Wars - from 101.63fps to 104.07fps average.
