We managed to get some information about AMDs upcoming Radeon HD 7970 GHz Edition. It will not only be clocked at 1 GHz but will also feature a new chip. This new chip as been named Tahiti XT2 and is able to operate at higher frequency with lower voltage.
Thank's to TMSC, whose 28nm process manufacturing quality is becoming better and better, AMD is able to release the second revision Tahiti XT2. For the record you will be able to find the Tahiti XT2 on the PCB of the new upcoming Radeon HD 7970 GHz Edition but not only. According to our source the Tahiti XT2 chip will be also powering the Radeon HD 7970 X2 for sure and maybe a new version of the Radeon HD 7950. About the new version of the Radeon HD 7950 nothing is sure but it might be possible.

About the new chip itself, there are two major improvements from the Tahiti XT to the Tahiti XT2. First of all the clock frequency will be at least 175 MHz higher for the Stock models as the XT is clocked at 925 MHz and the GHz Edition should be clocked at 1'100 MHz. Then the default voltage of the chip changes too going from 1.175 volts for the Tahiti XT to only 1.020 volts for the Tahiti XT2 which is almost 0.15v.

So in the end we will have a graphics card clocked higher that should be cooler and with lower power consumption. It will allow some margin to AMD in front of the GTX 680 from nVidia and maybe take back the leadership?

We don't know yet when these cards will make it to the market but we know that mass production starts next week.
Source: Own