Temps and overclocking
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 2,048MB | Force3D Radeon HD 4870 512MB | Sapphire Radeon HD 4850 X2 2,048MB | PowerColor Radeon HD 4850 512MB | BFG GTX 280 OCX 1,024MB | BFG GTX 260 OCX MAXCORE 896MB |
|---|---|---|---|---|---|---|
| Ambient temperature | 24°C | 23.5 | 22 |
25 |
22 |
21 |
| Idle temperature | 73°C | 78 | 42.5 |
77 | 54 |
42 |
| Load temperature | 95 | 90 | 62.5 | 82 | 74 |
64 |
| Ambient-to-load delta | 71 | 67 | 41 |
57 | 52 |
43 |
The time taken to bring a Radeon HD 4850 X2 to market clearly has its advantages in terms of refinement. Sapphire manages to keep its custom-cooled offering idling at 42.5°C, and its load temperature is lower than any of the other high-end cards in our test.
That's mighty impressive for a dual-GPU board , but there's a flipside to the surprisingly cool temperatures - we found the card to be loud both when idle and under load.
Overclocking
Irrespective of the board's low temperatures, Sapphire has opted not to raise Radeon HD 4850 frequencies right out of the box. We decided to have a play and managed to easily raise core and memory clocks from the default 625MHz and 1,986MHz to 650MHz and 2,036MHz, respectively.
That added approximately 2-3 per cent to the average framerate at 1,920x1,200, but we suffered from crashes when attempting to overclock further. An early driver problem, we feel, and we'd anticipate users will be able to push it further when used in conjunction with final Catalyst 8.11 drivers.
