Temperature And Noise
For the most part, idle temperature and noise measurements are pretty boring. We all know that these cards are going to run quietly- and coolly-enough when they aren’t being asked to do actual work. Depending on how much effort is put into a given product’s cooling solution, you might see lower-end boards running hotter than pricier cards—and that’s exactly how the GeForce GTX 670 stacks up to the 680. Despite a disabled SMX, the 670 idles warmer and makes more noise than its predecessor, likely as a result of a cost-reduced form factor.
Bear in mind, though, that many partner boards will employ alternative cooling solutions, and won’t be represented by these results.
The same holds true under load: GeForce GTX 670 is warmer and louder than the GTX 680—but only barely so. Though it isn’t as quiet as a Radeon HD 7950, which we really like for its acoustic performance, the 670 is notably quieter than the reference cooler on AMD’s Radeon HD 7970.
Though there isn't really a performance hit but it would be great to have seen the GTX 670 running at PCIe 3.0.
Nvidia has had a big lead in Dirt 3 and WoW for a very long time. This skews the results.
The GTX 670 is a fantastic card, don't get me wrong. Just pointing out that it's being slightly overrated here.