AMD issues statement on Radeon 4830

AMD has issued a statement on the Radeon 4830 issue, apparently a few hundred cards shipped out with 3 SIMD cores disabled:

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 (available at http://www.techpowerup.com/gpuz ). 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.

I'm nearly finished running the numbers now, so far the performance improvement is a pretty slim 3-6%.