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EMME/2 under SCO UNIX

As mentioned in the editorial, EMME/2 has now been ported to the SCO Unix operating system on INTEL machines. It is actually being tested internally at INRO, and should be released officially in a few months.

INTEL 486 based DOS machines rank very well on CPU intensive tasks, such as the EMME/2 fixed demand auto and transit assignments. On the other hand, disk intensive tasks, such as the variable demand auto assignment and matrix calculations, are very slow. By comparing two identical computers, one running under DOS and the other under Unix, we can now verify if it is the hardware implementation or the operating system that is the limiting factor. Is it worthwhile to transform a DOS machine into a Unix machine to gain speed? We will try here to give a few test results to help the decision making.

We compared two identical computers: two Compaq 486/25 with 6MB of main memory, both equipped with a Trident super VGA graphic card. The two FORTRAN compilers used to create the EMME/2 binaries are from the same company. Four benchmarks were used for the comparison:

The following table gives the final results, along with results obtained for other Unix workstations.

Fixed DemandVariable Demand
ComputerAuto AssignmentDBENCHAuto AssignmentGBENCH
1 it.Total1 it.Total
I486 DOS14.6174.8127.469.2852.28.8
I486 DOS with cache13.3149.740.027.7420.38.7
I486 SCO11.3122.316.216.3175.910.0
SUN SPARC SLC15.2167.014.919.0209.39.1
SUN SPARC IPX6.774.110.18.890.73.6
IBM 6000/320h5.459.08.86.975.63.3
HP 9000/7203.032.75.73.841.91.8
SUN SPARC SERV 33011.1121.815.814.6160.86.2

Clearly, DOS needs help when it comes to disk access. Installing a disk cache gives a 50% improvement, and once SCO is installed, the Compaq catches up with other Unix workstations having a similar CPU performance. With 33 and 50 Mhz I486, results ought to be even better.

Three points are worth mentioning concerning these results:

If your application is power hungry and you have an INTEL machine lying around, installing SCO might be an inexpensive solution to consider. If you can't stand living without DOS, note that SCO allows one to run DOS and Unix programs in parallel or use the station as a pure DOS machine.


next up previous
Next: Latest EMME/2 Benchmarks Up: EMME/2 News 12 December 1991 Previous: EMME/2 in the University -


Heinz Spiess, EMME/2 Support Center, Thu Jun 6 14:25:33 MET DST 1996