It is clear now, that AMD's next performance GPU, theRV790 will be built on the 55 nm manufacturing process. To build on this information, sources tell German website Hardware-Infos that one of the factors that will help the new GPU perform better and run at higher clock-speeds than its predecessor, the RV770 does, is the newer improved 55 nm manufacturing process it will be built on. Going by the foundry-partner codename "55GT", the RV790 may get a little help from its superior silicon fabrication, which invariably makes it more expensive to manufacture.

One of the reasons behind why AMD is starting its 40 nm GPU lineup with a mainstream GPU such as RV740, is that the 40 nm process needs further development by foundry companies. It hasn't developed to the level that safely permits manufacturing high-end GPUs with stellar transistor-counts. For the same reason, NVIDIA's 40 nm conquest will be flagged off by the entry-level GT218 GPU. High-density circuits builton the current 40 nm process are known to be very prone to electrical leakage.

RV790 engineering-samples undergoing testing are known to be coming in two flavours according to the source: a base model and an overclocked model. The base model comes with the same exact clock speeds as the RV770XT: 750/900 MHz (core/memory), while the overclocked model is known to come with clock speeds of 850/975 MHz (core/memory). To achieve that 100 MHz increment in core frequency, the voltage is known to be stepped-up from 1.24 to 1.30 V. Products based on this GPU are known to surface by April.