Our tests of Radeon HD 6770 and HD 6750 cards have gone just as expected. These are mainstream cards with rather low gaming performance and almost indistinguishable from the older Radeon HD 5770s and HD 5750s. They are slow in most of today's games, so we can't recommend them to serious gamers. You can’t improve their performance much through overclocking as they don’t have high potential for that. On the other hand, they are affordable and can be a perfect choice for quiet or even completely silent computers. That’s why we’ve selected passively cooled versions of these cards for this review.
The ASUS Radeon HD 6770 DirectCU Silent features the most efficient fanless cooler of the three. With a heatsink that big, you should have no worries about the temperature of the GPU and the graphics card at large. The downside, besides the somewhat higher price compared to the reference card, is that the ASUS version has large dimensions and will not fit into some computer cases, especially compact multimedia ones. This card lacks a CrossFireX connector, has a reduced memory clock rate and comes without any extras among its accessories.
The Gigabyte Radeon HD 6770 Silent Series is the fastest card of this review. It is no more than 15% slower than the more expensive Radeon HD 6790. Its fanless cooler copes well and makes the GPU comfortable even at overclocked frequencies. Like the ASUS card, this one has large dimensions which may make it incompatible with some system cases. We can see no other downsides about the Gigabyte version, though.
The PowerColor Go! Green Radeon HD 6750 Dirt3 Edition is the slowest but also the most economical card among the three. As opposed to the other two, it has no connector for additional power supply. It can be overclocked a little and is much smaller than the ASUS and Gigabyte cards. Thus, it may be the only option for compact system cases among these three products.