Temps, power-draw, and a note on noise
A failing of the Radeon HD 4870 was its idle temperature. It's easy to spot here.
Power consumption
And the power-draw is none-too-handsome on the Radeon 4-series card. Heck, it makes GeForce 400-series cards seem frugal in comparison.
Tying in with the temps, the HIS HD 6870 requires a few more watts than a Radeon HD 5850. We've seen partners launch custom-cooled HD 5850s with near-silent cooling and expect the same to happen with the faster Barts card.
Sapphire's Radeon HD 6850 performs well and is frugal with respect to power. Indeed, it's more energy efficient than any NVIDIA card in this line-up.
Noise
Sapphire's card is near-silent when running 2D tasks and the fan is
only noticeable after FurMark has been running a while. Play regular
games and you'll be hard-pushed to hear it at all.
The reference-based HIS Radeon HD 6870's fan is louder at both idle and
load levels. While patently not in the same league as the turbine-like
noise emitted by GeForce GTX 470/480 when under the hammer, the fan is
noticeable during gaming. In fact, it sounds very much like a Radeon HD
5850, which is hardly surprising given the similarities between the
GPUs' TDP and coolers.
