Talk about back with a bang.Having been relatively disappointed with the performance of the HD6 series, the HD7970 was a stunner. AMD aimed squarely at the GTX580 and definitely achieved their aims.Of course, as with all premium products, there is a heavy price-tag to pay for that performance. So far more of us have been waiting for the release of the HD7950 to see if it's a repeat of the excellent 4850 (very close to its bigger brother), or more akin to the 6950 (only really useful in Crossfire).Wonder no longer as we are here with the first of three HD7950 reviews today.First up we have the reference model, here brought to us via the fine folks at HIS Digital.