AMD had a bit of a goofup on their hands. Last week this news already reached us yet seemed limited to press members (samples). Apparantly a batch of their cards has received an improper bios disabling a shader cluster on the Radeon 4830 graphics card. Some members of the press have actually published a review with the wrong shader amount (560 Shaders out of 640). Next to that an early batch from HIS technology also seems to have this issue (our review sample was okay by the way).

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 here). 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.

HIS is preparing a new BIOS for those effected by this week. Thanks Watcher for the initial info on this. But now the real question remains, since everybody expected the shader limitation to be a on die laser-cut ... can we alter the BIOS to enable all 800 shaders ? ;)