Overclocking
Like with the vast majority of HD 7790’s our overclocking was cut short by unremovable Catalyst Control Centre OverDrive limits. These limits can only be removed with advanced BIOS tweaking. That said our overclocking session ended by maxing out the limits at 1200MHz core and 1600MHz memory. In terms of clock gains we made 6.7% on the memory and 11.6% on the GPU core. In terms of the results that achieved us we increased our 3DMark 11 Performance score from P5907 to P6278 which is a 6.3% real gain in performance. So overall there is a decent amount of extra performance from overclocking but it is heavily limited by AMD’s BIOS limitations – not something we can really penalise Gigabyte for.
at £125, it takes it into 7850 1gb territory, I concur with your conclusion, its certainly overpriced, and limited by that 128 bit bus width, for the same money you could get the 256 bit 7850 1gb, the memory throughput is so much better, and will allow the VRAM to be overclocked, SCAN has an MSI 7850 1gb for just £123.34, making this 2gb 7790 variant redundant.
http://www.scan.co.uk/products/1gb-msi-radeon-hd-7850-4800mhz-gddr5-28nm-gpu-860mhz-1024-cores-hdmi-2x-mdp-dl-dvi-i