Check out these quotes from PowerColor Radeon HD 5870 reviews & previews
"During a Radeon HD 5800 series launch event recently, ATI told the press they wanted to change the game. Well, it seems that they have done it. The new Radeon HD 5870 is nothing short of spectacular, as it provides great performance and class-leading power efficiency. The next six months will be interesting as they'll be expanding the Radeon 5000 series. Meanwhile, the green camp has remained suspiciously quiet, and not much, if anything at all, has been heard of the upcoming GT300 series.
To conclude, it is without a shadow of a doubt that the Radeon HD 5870 is the new GPU kingpin. ATI has drew first blood, now it's time to see how NVIDIA will retaliate."
"PowerColor's HD 5870 PCS+ is one amazing piece of hardware. It offers enough 3D performance for any title, at any resolution, at any details setting, yet it runs so quiet. PowerColor's latest card is probably quieter than most midrange and low-end cards on the market today. With such a noise profile it could even end up in a media PC that is sufficiently quiet to not be disturbed during movie watching but also packs enough punch to play the latest titles on the big screen.
While the overclock out of the box was quite slim our card showed great overclocking potential when done manually, reaching the magic 1000 MHz mark. I am quite certain that AMD limits AIBs to certain clock ranges and does not allow any higher overclock. The performance increase from the reference design frequencies is marginal with only 3%, a difference not noticable in games. Overall it seems PowerColor designed an amazing card that also comes at a reasonable price increase. $10-20 over the reference design price of ~$400 is about 3-5%, hardly worth mentioning."