Power And Noise
ATI rates the Radeon HD 5770 for 18W of power consumption at idle and 108W maximum board power at load. The Radeon HD 5750 is even lower at 16W idle and 86W under load. The delta there checks out almost exactly, as our Radeon HD 5750 sample used two watts less than our 5770 at idle, and 22W less (instead of the expected 21W) with FurMark running at full tilt.
The only card in this lineup able to use less power at load is the Radeon HD 4770—though it consumes more power at idle than either of the 5700-series boards.
Nvidia’s G92-based GeForce GTS 250 and GT200b-based GeForce GTX 260 lay down impressive idle numbers, given the fact they’re manufactured using 55nm technology. They can’t compete with the power savings of ATI’s 40nm boards under load, though (the exception being the power-hungry 5850).
We were much more concerned with noise last month. The flagship cards push the envelope, generating the most heat under duress. When the same technology is derived down into the mid-range, it’s rarely as hot or loud.
Indeed, all of these boards are able to idle along fairly quietly with complete systems generating less than 40 decibels. With a FurMark stress test running, fans are forced to keep temperatures under control, but never really need to operate at full tilt. All of ATI’s 40nm GPUs turn in fairly similar results, and even the CrossFire configurations aren’t intrusively obnoxious under load.