Bit-Tech are reporting that ATI has finally admitted to the strange goings on with its HD 4830 graphics cards.
Bit-Tech and other hardware review sites noticed that after benchmarking, there were too many variances in the results and some cards were a lot slower than others, even though they were supposed to be identical review units.
It was later discovered that the strange results were the result of some cards only using 560 of the total of 640 stream processing units available, hence the lower scores.
Last week AMD has put out a statement that they were "aware of the issue" and now they have gone further and told the full story:
"AMD has identified that, in addition to reference samples of the ATI Radeon HD 4830 boards sent to media with a pre-production BIOS potentially impacting the card's performance, a very limited number of ATI Radeon HD 4830 boards were released to market with the same pre-production BIOS. This is in no way hardware related, and an updated BIOS fully resolves the performance limitation.
Through consultations with AMD board partners, it has been determined with a high degree of certainty that fewer than 400 ATI Radeon HD 4830 boards from one AMD board partner, HIS, have reached the market with the pre-production BIOS incorrectly provided by AMD. As only a small number of HIS-branded ATI Radeon HD 4830 cards are impacted, we ask any customers that purchased an HIS-branded ATI Radeon HD 4830 to test the board using the GPU-Z utility. If the GPU-Z utility reports fewer than 640 shaders, please visit the HIS website for information on how to update the card BIOS via a downloadable install utility."