we have already reported several times that one could easily overclock a Radeon HD 4890. Several manufacturers decided to offer an overclocked version of the Radeon HD 4890 with a GPU clocked at 1 GHz, for obvious marketing reasons. Of course, they would then benefit financially from such overclocked product. AMD quickly reacted to avoid loosing market share and officially announced its own 1 GHz Radeon HD 4890 model.
The only noticeable difference is the heatsink, with a different design and probably a better performance level. By releasing officially this card, ATi/AMD becomes the first GPU founder to reach/break the 1 GHz barrier on the electronic consumer market.
however, one should keep in mind that the battle around GPU performance level so far limited on Mac, will soon be unchained, as with Snow Leopard and Open CL the GPU will now massively be involved in our computers. this could also explain the current rumors regarding the future availability (from June?) of NVidia retailed Mac graphic cards independently of the Apple Store.
