Silicon Graphics Inc has boosted the top-end performance of its three-dimensional graphics workstations with a new top-end model – the 4D/80GT, and has made a move into multi-processing with a new upgrade facility for Iris workstations. The 4D/80GT uses the faster 16.7MHz version of the R2000 RISC processor from MIPS Computer Systems to boost performance by 30% over the previous models based on the 12.5 MHz chip – and at UKP68,000 in the UK has a price increase of only 10%. And the company has also introduced an upgrade option for its Iris range, which includes dual 16MHz RISC processors and proprietary VLSI chips to boost the graphics subsystem. The GTX upgrade for Iris 4D/50, 4D/70 and 4D/80 models is claimed to result in systems rated at 20 MIPS and 2MFLOPS, and has doubled graphics performance, transforming 150,000 independent, gouraud shaded polygons per second, with a pixel fill rate of 8m pixels per second. The two processors communicate through a high speed VME-like bus developed by Silicon Graphics, and UK managing director Tim Marlton hinted of further ventures into multi-processing with forthcoming products. In the UK, it will cost UKP19,000 to upgrade the 4D/80GT, UKP30,000 to do the 4D/70GT, and UKP41,000 to revitalise the 4D/50GT.