Multiprocessor Systems: The Other Benefit

Setting up the AnandTech test bed, the Epox Dual Processor BXB-S Intel 440BX based motherboard was used as the heart for the Dual and Single 266/400MHz systems. A single 128MB Mosel Vitalic Memory Man SDRAM DIMM was installed in the first memory bank, and the rest of the configuration was as follows:

• 9GB IBM Ultrastar Ultra Wide SCSI-3 HDD
• Matrox Millennium G200 (16MB) AGP Video Card
• Microsoft Windows NT Workstation 4.0 with Service Pack 4 Installed
• The latest device drivers as of January 23, 1999 were installed
• All tests were run at 1024 x 768 x 16-bit color at a 75Hz refresh rate

The software benchmark suites involved MP3 decompression (incredibly CPU intensive) using Winamp 2.09, with the WAV Mapper set as the output device (decompressing the MP3 files to disk) while running Business and High End Winstone 99 tests simultaneously. The size of the MP3 files decompressed amounted to 1.85GB on a separate partition of the test system's hard disk, and the entire decompression did not complete before the end of the Winstone tests as to simulate a true, stressed, multitasking environment.

As you can see, the performance of single processor systems under multitasking environments is much lower than that of dual processor systems under the same conditions, which is to be expected. The interesting points to notice are that the difference between a dual Pentium II 266 and a single Pentium II 400 in general multitasking performance benchmarks still favors the single Pentium II 400 due to its sheer advantage in processing power over the dual 266. While that may not apply to high-end applications, it does apply to this scenario illustrated by AnandTech for the other type of multiprocessor user.

Giving users more than just a faster way to render huge image files or calculate the dimensions of a skyscraper, multiprocessor systems do allow for incredible multitasking capabilities, unfortunately they aren't great enough to justify slapping in 2 slower processors in favor of one faster unit; unless of course you happen to be doing some high-end work on the side.

The big question seems to be, will adding a second processor speed up tasks such as parallel port accesses (i.e. Parallel Port ZIP drives, etc…) and floppy disk accesses? The answer is unfortunately no. Demanding I/O tasks such as those mentioned need to be offloaded onto another processor other than your main processor subsystem, luckily Intel did happen to create an embedded processor that would handle just that, it's name and it's function in the next update to the Multiprocessor System series on AnandTech.