Computer museum: Processor power

Processor power

Problems

Measuring processssor power over a number of years causes a number of problems:

Measuring machine capacity

Around 1975 the speed of a machine was given with the cycle time of its memory (Varian and PDP).

From 1978 on, after the introduction of the Vax 11/780, the processor speed was expressed in Vax Mips (Mega Instructions Per Second).
Measuring Vax Mips (in short Mips) was done with test programs and the programs used could influence the results/ Floating point performance was measured in Mflops (Mega Floating Point Operations Per Second). obviously with the same problems as Mips.

Aroung 1988 it became custom to use standard test programs to measure processor speed. The programs were fixed and the result was given in

SpecInt

for operations with integers

SpecFloat

for operations with floating point numbers.

The first program version measured SpecInt89 and SpecFloat89. Later followed by SpecInt92, SpecFloat92, SpecInt95, SpecFloat95.

Moreover these tests were not suitable for multiprocessor machines and teherfore SpecIntrate and SpecFloatrate were used ...

Since al these data cannot be converted from one unit into another, we use in our diagrams Mips (Meaningless Indicator of Performance). Between 1979 and 1989 our mips corresponds to Vax Mips. Before 1979 we use estimates based on personal experience. After 1989 we converted SpecInt using the ratio observed from the few machines when both specint and mips were used.

The data is taken from the spec's of the computer manufacturer at the date of our purchase.

Servers and workstations

The departement did divide its machines in

The graphs always show a server only line, but you will also find a graph were both servers and workstations are included.

The processor capacity of machines used only as display (e.g. Xterminals) is not included, neither are PC's.

Cumulative processor capacity

 CUMULATIVE PROCESSOR CAPACITY (LINEAR AND LOGARITHMIC)

Cost per Mips

This graph shows the cost per mips. To construct this graph we took the total purchase price of the machine and divided by its Mips. The fact that different disk size are included is not considered as error, since disk space needed per user and per system did continuously increase in time.

Included in the graph:

 COST (BEF)/MIPS (LINEAR AND LOGARITHMIC)

Copyright ©2001, Katholieke Universiteit Leuven, Departement Computerwetenschappen Comments to: Curator URL of this page: http://www.cs.kuleuven.be/museum/getallen/mips-E.html : Click here to print this page