dual (SMP) Pentium III processors. The 540 and 550 models support the Xeon implementation of the Pentium series, and could support up to four Xeons in an SMP configuration (only two for the 550). Although no SGI Visual Workstation was ever released with a CPU running higher than 700 MHz, some hobbyists have been able to run faster processors. For the SGI 320, the limit is dual 1 GHz Pentium III processors or a single 1.4 GHz Celeron. Dual 1 GHz processors require a specific model of CPU, which is intended for Intel servers. Further, the voltage regulator, PROM, and revision of the motherboard also have to be correct for the setup to work. With single processors the Powerleap Pl-iP3T "slocket" adapter and a Tualatin 1.4 GHz Celeron processor is the limit, and is a straight bolt-in installation. The Tualatin core gives a more modern processor, and the Powerleap adapter handles the voltage regulation to the CPU. The SGI 540 has been reported to handle up to 900 MHz quad Xeon processors. These are the fastest Pentium III Xeons with the 100 MHz front side bus speed of the 540. The 230, 330, and 550 models are essentially standard PCs and has the same capabilities and upgrade limits as other PCs of the time. The 230 and 330 are based on VIA chipsets, used socket 370 processors, and conventional SDRAM. The 550 used Slot 2 Xeon processors, the Intel 840 chipset, and RDRAM. The video cards these systems used are Nvidia AGP cards based on the Quadro 2 chipset, and differ from aftermarket Quadro GPUs in their drivers. References External links Unofficial SGI 320 Visual Workstation website SGI legacy page for Intel based systems SGI site for Linux on i386 (including Visual Workstation boot floppies) SGI Visual Workstation information page Linux for SGI Visual Workstations Installing dual 1 GHz Pentium III (100 MHz FSB) CPUs SGI workstations Advanced RISC Computing 32-bit computers