Thirty Years of Progress in Computing

How do Megaflops and other attributes compare to today?

Trying to compare MIPS, Megaflops, or even equivalent memory sizes, is fraught with questionable assumptions and "yes but -" issues. Such artefacts are very hard to compare in any meaningfull way. Nevertheless, it can be fun to just get some rough idea of the magnitudes involved.

As a starting point, many people have taken a 16Mhz Intel processor as being a base equivalent to about one MIPS. Clearly one Megaflop takes more horsepower than one MIPS, but extrapolating say a 20Mhz Intel processor to be about one Megaflop is not unreasonable. ("Yes but - what about word size? What about cache and memory bandwidth?" I hear you say. Granted - but we are only doing a very rough order-of-magnitude comparison here.)

Around the year 2000, we can talk about a 1 Ghz Intel laptop, (roughly equivalent to 500 Megaflops) 128 Meg of memory, and say 30 Gigs of diskspace for around $2000.

In 1970 we spoke of a 6600 with around half a megaflop of compute power, 128K 60-bit words of central memory, and a Bryant disk holding the equivalent of around 75 Mbytes of 6-bit characters. (That was the big disk with the horizontal shaft holding six 1-meter platters and hydraulically actuated heads.) All if this for around $5 million, including motor generators, water-cooling, and false-floors. If we take inflation of the dollar into account, and benchmark a 1970 middle-class 4-door sedan ($3,000) to today ($24,000) then the $5 million is really around $40 million in equivalent dollars.

In terms of power, (and neglecting the energy required to run the water chillers) we are talking of a 100-amp supply at 440 volts versus a brick whose output is rated at 2.5 amps/20 volts; say 44,000 watts versus 50 watts.

In terms of mass, assume the central processor, disk, and power-supply (motor-generator) at 4 tons, 1 ton, and 1 ton respectively, for a total of 6 tons (neglecting printers, card-readers, tape drives, underfloor cables, sundry controllers, etc.) versus around 5 lbs for our laptop, power-brick and mouse.

Given all of these tenuous and arguable assumptions, (and equivalencing a 6-bit character to an 8-bit byte for the sake of argument) we come up with the following ratios:

What 30 Years Have Wrought   ( And a further 15 years )

    1970         2000     Approx. Ratio 2015 Update
Compute Power (Mflops)0.55001,000  77,000*
Central Memory (Executable) 128K*10128 Mb100  1,000 Mb*
Disk Space (Data Storage)75 Mb30 Gb400  64 Gb (Solid State)
Power Requirements (Watts)     44,000501,000  0.5
Physical Mass6 Tons5 lbs2,500  4 oz
Cost$M40$K220,000  $800


(An extra column was added to the table in September 2015 reflecting the appropriate values for a current smart phone, thanks to a suggestion by former colleague RRR.)

* Note that the 77,000 Mflops is achieved by a GPU - Graphics Processing Unit (as opposed to a CPU) with vector processing capabilities, much as the earlier Cyber 2000 could employ in its day to achieve its (then) spectacular performance, and that the remarkable memory size of 1,000 Mb is in fact just another way of saying 1Gb which is how we express things today..


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