5770 to 6770
Though the majority of the HD 6xxx series features the Northern Island family of graphic processing units, both the HD 6770 and 6750 continue to use the Evergreen-based Juniper cores. As hinted at previously, this makes the HD 5770 and 6770 very, very similar. In fact, it's not just Sapphire's packaging that is identical; specs for the OEM card such as Stream Processors, Core Clock, memory clock, number of transistors, and texture units are all the same between the two cards.

Sapphire's FleX edition of both the 5770 and 6770 tells the same story. Both features a 850MHz core clock speed, 40nm chip, and 800x Stream Processors., with a 1024MB and 48000MHz memory speed.

So, what's with the repackaging? One of the main reasons is the discontinuing of the ATI brand. The Northern Islands GPU family marked the official end of the ATI brand, with the 5770/5750 still competitive but missing the new graphic logo of AMD graphics. The HD 6770 can now be issued with the correct AMD logo, though ironically our test sample still features an ATI Premium Graphics badge.

Another reason is support for HDMI 1.4a, which was released early this year in March. While HDMI 1.4 support stereoscopic 3D, formats were intentionally excluded until the ultimate fate of 3D could be determined (this was in 2009). The 67xx is now on par with the rest of the 6xxx Northern Island cards, supporting frame packing and resolution through 1.4a. In addition, an improvement to the Unified Video Decoder (UVD) allows for a more expansive decoding of resolutions and bitrates, especially for Blu-Ray 3D technology.