Symmetric Multiprocessing

Four is better than Two

There has always been a draw to the idea of potentially doubling the speed of your components by using two of them in parallel. A few years ago, Mr. BIOS released a BIOS that would allow for firmware support of RAID 0 disk striping on standard EIDE hard drives (several hardware products allowing for the same capability exist to this day). For the power user, the idea of running two hard drives as one and theoretically doubling transfer rates without the cost of SCSI RAID was an enticing deal.

3dfx's Voodoo2 solidified the "2 is better" mantra with its famous "SLI" mode, allowing two V2s to run in parallel, doubling the effective fill rate of the already-top notch 3D performer. As evidenced by Metabyte's PGP/PGC technology, the demands of today's high-performance user makes the many forms of multiprocessing technology that is much more in demand than in previous years.

CPU Multiprocessing has been with us for quite a while, but has only recently reached a point where it can be considered cost-effective for most users. The Pentium II and Pentium III have intrinsic support for 2-way multiprocessing, making it relatively painless for those seeking instant upgradability. What the Xeon line has offered is scalability past 2-way multiprocessing, making it a more attractive model for high-end workstations and servers.

Chipsets

While the processor has built-in support for multiprocessing, the motherboard chipset plays a big part in its implementation. The current Workstation chipset, 440GX, is merely a slight reworking of the workhorse 440BX for slot-1 CPUs, and only allows for 2 processors. The 450NX is the current high-end Xeon chipset, and has added support for 8GB RAM, multiple PCI busses, and of course, 4-way multiprocessing.

Intel is already planning for the future of Xeon, with the planned Carmel and Profusion chipsets. Carmel is planned to be a workstation solution, and will probably mirror Intel's mainstream Camino chipset very closely, offering 100 or 133Mhz FSB, AGP4x, and UDMA/66 support for future P3 Xeon processors. Early indications show that Carmel may have support more than Xeon processors (allowing 4 or even 8-way multiprocessing).

Profusion will be the next iteration of 450NX, Intel's highest-end sever implementation, and will probably remain 100Mhz, but adding support Direct RAMBUS DRAM and/or DDR SDRAM for higher data transfer rates to and from memory, as well as support for 4-way and 8-way multiprocessing.