ATI Technologies chief executive officer recently said that sometime in future consumers will be able to get graphics sub-systems featuring four visual processing units. The head of the world’s largest supplier of standalone graphics processors did not comment when would it happen and what challenges should be resolved to create such hardware.

“On the consumer side, in the future I could expect to see a display card that includes two graphics chips, which could be combined to provide a four GPU solution,” Dave Orton, chief executive officer at ATI, told Muropaketti web-site in an interview.

Earlier this year a number of companies, including ASUSTeK Computer , Gigabyte Technology and Microstar International (MSI) introduced their graphics cards with two GeForce 6-series graphics processing units that worked in NVIDIA-developed multi-GPU mode dubbed SLI. Neither of the graphics cards could operate in dual-card mode allowing four graphics chips to process a frame.

ATI’s CrossFire consumer multi-GPU technology, which was introduced in late-May, 2005, has yet to come to the market. The method of linking two ATI RADEON graphics requires a set of chips called Compositing Engine. Theoretically, two or more such engines could allow four-way graphics sub-systems for unbeatable performance in 3D applications. No companies, however, indicated plans to build graphics cards powered by two ATI RADEON visual processing units.

A pair of two graphics cards based on two high-end graphics processors would cost about $1500 and will require a computer system with top-end central processing unit and high-performance power-supply unit.

Representatives for arch-rival NVIDIA Corp. earlier this year also did not exclude possibilities to introduce four-way graphics sub-systems with its SLI technology. ATI’s arch-rival spokespersons declined to elaborate on principles of the technology.