The AMD Radeon HD 7770 GHz Edition and Radeon HD 7750 graphics cards have come to replace the Radeon HD 6770 and HD 6750 and are indeed faster, yet not fast enough to compete with Nvidia’s previous-generation solutions, particularly the GeForce GTX 560. In fact, the Radeon HD 7750 ($109) can’t be viewed as an entry-level gaming card since its performance is too low even for 1920x1080, which is the lowest standard resolution for a gaming computer. The Radeon HD 7770 GHz Edition is somewhat more interesting but seems to be overpriced at its $159, so we expect it to get as cheap as $139 and thus avoid the comparison with the GeForce GTX 560 which is obviously faster. Instead, it should compete against the GeForce GTX 560 SE or even the GTX 550 Ti.
It is a shame that despite the low memory prices and the new GPU tech process AMD still equips its junior graphics cards with a 128-bit memory bus which cannot be compensated by the high clock rate. You can take a look at the results of the Radeon HD 6870 or GeForce GTX 560 with their 256-bit bus to understand the problem.
Another problem is the large performance and price gap between the Radeon HD 7770 GHz Edition and Radeon HD 7850. AMD should fill it in quickly before Nvidia does the same.
That said, we still want to praise the new AMD cards for their good energy efficiency, compact design and support for all popular interfaces and technologies. You may want to choose one of them for a modest gaming computer.