Enthusiasts have to a certain extent criticised the AMD HD7970 for what they perceive to be an overly conservative stock GPU clock speed of only 925 MHz, given that review sites and end-users alike have reported overclocks to 1GHz+ almost as a matter of course. This was exacerbated by the release of the GTX 680, which used GPU Boost technology to overtake the stock 7970. With VGA overclocking still relatively rare amongst gamers AMD was on the back foot, maybe playing it safe because of the desire to launch in high quantities and not going overboard on what was still a new 28nm process.
Speculation of an AMD 7970 GHz Edition, using the same Tahiti XT GPU but a clock-speed bump from the stock 925MHz, has been rampant ever since the brand was released with the unveiling of the HD7770 in February. In recent weeks however rumours have gained strength and appear to have peaked with this article from Softpedia pointing to leaked review benchmarks comparing an HD7970 GHz Edition with an NVIDIA GTX 680. It's believed that the decision to release a GHZ Edition is not down to significant improvements in the core so much as far better binning of chips capable of >1GHz frequencies, perhaps with <1GHz now going to dual-GPU cards. Sadly we still don't have anything concrete to report, and as Softpedia state availability and price are key unknowns.
Coupled with increasing high-end speculation, including the already known 7970X2 from the likes of HIS and Powercolor, is a refresh to the lower performance lines. 3DCenter.org (German translation) report that new iterations of both the Cape Verde-based 7770 and 7750 are due this month which should result in a speed bump to compete with the incoming GeForce 640-series. As the GTX 650's and 660's from NVIDIA are still AWOL (excepting the mobile 'M' variants) AMD are no doubt keen to sow-up their dominance whilst addressing some of the key criticisms of the 7770 - that it doesn't quite provide enough of a boost over last generation parts.
Most outlandish of all however is the note that potential 7930 and 7830 cards will be incoming late this summer. Recent driver Beta's indicated that a Tahiti LE GPU may be on its way, possibly in the form of 7900-series card with fewer Compute Units but an identical memory bus width. Late generate salvage parts are often mixed in their reception; the HD5830 was not thought of particularly highly, but the 560 Ti 448 (in reality a cut-down 570/580) has proved to be a good value purchase as prices came down. Whilst the overclocking potential of the 7850 and 7870 remains good with a relatively small price differential to the 7950 a 7930 seems like an odd product, however a 7800-series price drop upon the release of the 660-series may see a gap in the market appear.
Similarly, an 7830 would be an odd part, but the significant price and performance gap between the 7770 and 7850 makes it appear to be a good idea now, never mind the end of the summer.
Hopefully we'll see and hear more from AMD soon, as they've been a little quiet on the GPU front since Pitcairn's release. And of course this is not to mention the 8000-series, expected late 2012, for which there was also some intriguing news today.
Source: 3DCenter.org, Softpedia