Sun Microsystems Inc’s processor arm is creating a new line of ‘system-on-a-chip’ RISCs from its 64-bit UltraSparc design which the system side of the company will use to improve the lacklustre performance of its low-end uniprocessor workstation line. Sun doesn’t want to say it in as many words but UltraSparc i looks like the part originally known as microSparc III, conceived as a shrunken – therefore faster – micro-Sparc II, then re-focused as a microSparc-compatible Sparc V9 architecture UltraSparc core device (CI Nos 2,829, No 2,916). The first iteration of the UltraSparc i series is due from the end of next year as a 300MHz device delivering 10.6 SPECint95 and 14 SPECfp95 performance, which is as much as seven times greater than the performance of the 110MHz microSparc II Sun currently uses in the SparcStation 5, but not that much different from UltraSparc SPECmarks. It will supposedly reduce system cost by integrating main memory and system bus interfaces – it retains a ‘slave ‘ implementation of Sun’s proprietary UltraSparc Port Architecture bus for graphics but not for memory – and supporting lower-cost memory chips. Microprocessor Report notes that the chip itself will be no less expensive to fabricate than UltraSparc. It uses an integrated PCI bus interface, presaging, the Report believes, a move from Sbus to PCI in Sun’s workstations – but PCI add-in vendors will have to convert their drivers for Sparc before their boards can be used in UltraSparc i devices. Up to 2Mb of secondary cache can be attached as UltraSparc’s direct L2 cache interface is retained, although it has been chopped down to 64-bits from a 128-bit data path. The design retains Ultra-Sparc’s key Visual Instruction Set multimedia extensions. The more integrated UltraSparc i design sits between microSparc – now refocused as an embedded part – and full-blown UltraSparc lines. There will be a 300MHz, then mid-200MHz and possibly a 150MHz low-power version of the architecture for embedded systems. The first iteration of UltraSparc i, dubbed 1.0, is due to tape out this quarter, sample in the third quarter of next year and go into production in the fourth quarter of next year. 2.0 will tape out by mid-1997. Its not clear who is fabricating the Ultra-Sparc i in a 0.35 micron, five-layer metal process, although Sun handed manufacture of the part previously known as microSparc III to NEC Corp. Fujitsu Ltd fabricated microSparc I and II and has disclosed its own plans to upgrade microSparc installations with TurboSparc. Microprocessor Report believes the performance boost UltraSparc i will deliver to Sun’s low-end workstations is needed to match the performance of Pentium Pro and increasing viability of Windows NT as a workstation environment. Sun says it is disclosing its processor plan for UltraSparc i earlier than it would for other chips because it wants customers and the industry to understand it hasn’t given up on the low end in its quest for the higher ground. It is also trying to establish an UltraSparc brand identity, a la PowerPC
