For years clock-speeds of graphics processors were in the range of 500MHz or so since designers of those chips believed that there are more efficient ways of boosting performance levels of their products, for instance, the increase in the number of arithmetic logic units. However, this year in addition to tremendous increase of complexity graphics processing units (GPUs) obtained ability to operate at extremely high clock-speeds of beyond 600MHz.

The first GPU to surpass the aforementioned barrier was the RADEON X1800 XT that is clocked at 625MHz by default and can be set to work in the range of 675MHz ?700MHz. The second clock-speed champ is the GeForce 7800 GTX 512, a flavour of the GeForce 7800 GTX that operates at 550MHz instead of 430MHz and can be easily overclocked towards 600MHz. Several graphics card suppliers decided to take advantage of this and released graphics boards that are pre-overclocked by default and offer performance higher compared to similar products by others.

Two of such products that come with boosted performance right out of the box are EVGA e-GeForce 7800 GTX BlackPearl 512MB (600MHz/1800MHz for chip/memory) as well as XFX GeForce 7800 GTX 512MB DDR3 XXX Edition (580MHz/1730MHz for chip/memory). Apparently, even those products still have potential for further performance increases for those who would like to squeeze all the juices out of them.

Hexus.net web-site has decided to check out the overclocking potential of the fastest graphics cards supplied by EVGA and XFX and, in fact, succeeded in beating performance records with boards functioning stably at 638MHz/1840MHz and 616MHz/1790MHz respectively.

?A standard, always-available clock level of 600/900 makes for drool-worthy performance, with even more possible if you fancy getting your hands dirty with the likes of RivaTuner. In short, it's the fastest graphics hardware HEXUS have ever tested, and indeed are likely to test in 2005, this reviewer guessing that a 700MHz X1800 XT OC won't be enough to keep pace across the board,?said Ryszard Sommefeldt, a reviewer from Hexus.net, about the EVGA's top-of-the-range board.

• Hexus.net: EVGA e-GeForce 7800 GTX BlackPearl 512MB.
• Hexus.net: XFX GeForce 7800 GTX 512MB DDR3 XXX Edition.