Roughly a month after ATI, graphics business unit of Advanced Micro Devices, unveiled its ATI Radeon HD 4890 (RV790) graphics processing unit (GPU) and implied on its high overclocking potential, several leading makers of graphics cards started to show off their products featuring RV790 operating at a rather unprecedented 1GHz (or close) clock-speeds.

Massively factory-overclocked graphics cards are nothing new for the market, as they have been available for years, but this time MicroStar International, PowerColor and Sapphire Technology are hitting “magical” 1GHz milestone with a high-performance graphics chip. Considering that the default frequency of the RV790 is 850MHz, 1000MHz version should provide rather substantial performance boost, but is also likely to cost considerably more than standard flavours, which retail for about $249.

PowerColor, a well known supplier of graphics adapters, has already released its PowerColor PCS+ HD4890 graphics card with 950MHz graphics processor, 4400GHz memory frequency and special cooling solution from Zerotherm. There are talks that the company may boost clock-speed of the GPU to 1000MHz with some additional tweaks.

Sapphire Technology, which is the largest producer of ATI-based graphics adapters, is about to release its Sapphire Radeon HD 4890 Atomic with 1GHz graphics processor as well as 4200GHz memory. The “Atomic” will utilize special vapor chamber cooling system to keep the core cool enough to remain stable.

There is also chatter about special edition ATI Radeon HD 4890 graphics boards from other manufacturers, such as XFX, which will also be able to boast with 1GHz core clock-speed.

ATI RV790 graphics processing unit features 800 stream processors, 40 texture units, 16 render back ends as well as 256-bit memory bus compatible with GDDR3, GDDR4 and GDDR5 memory types. The RV790 chip is designed from the ground up to achieve considerably higher clock-speeds compared to reference 850MHz without loss of stability or degradation.

Tags: ATI, AMD, Radeon, RV790, 55nm