I was actually just scrolling around your webpage and was surprised when the blog got updated while I was cruising. There is no “bad time” for a blog post on the Internet.

Well if you use the CPU frequency as was estimated in this Wikipedia Article then the computing power of the Raspberry Pi is 128.69 times more powerful than the Colossus Mark 1 (5.8Mhz).

http://en.wikipedia.org/wiki/Colossus_computer

if i was so inclined i’d say the best was to work out how many collosii there are in a raspberry pi would be to impl. the algorithm that the colossus used and run it on the raspberry pi. i believe that a few years ago someone did it using Ada. This might be a good exercise to give the kids to keep them out of trouble :)

oh and i believe the ssh password is either “mooncake” or “liz4queen”

sry but you dont just just ssh in your own ssh

I read it as “what’s the difference in size per compute power”. If you take “compute power” to mean 1/(task duration). it suggests comparison of these quantities: (volume of colossus)/(power of colossus) = (volume of colossus)×(task duration on colossus) and (volume of Raspberry Pi)×(task duration on Raspberry Pi). I think it would be interesting to see.

MIPS per m³

Might consider comparing MTBF… Or even MTTR.

How about BTU/Ton?

Have an 8 vs 8 deathmatch on Quake III?

8 on the Pi, 8 on the Colossus, whichever team wins = most powerful computer, and the difference in kill/death ratio is the difference in computing power.

Now that’s a scientific experiment I want to be involved in!

The only meaningfull way I can see to compare the Pi and Colossus would be to code up an efficient version of what Colossus does on the Pi and compare time to run a task on each.

How was Captain Kirk then?

42 ?

I suppose you could time how long it takes to count to a million?

“but it turns out that Eben left the bit of paper on which he’d scribbled the credentials he needed to SSH into the server on my desk in the UK”

Writing this down, is this wise?

Schüth’s 5.8MHz number isn’t very interesting, as he was using different algorithms, a high-level language, etc. Colossus compared two text streams at (a configurable speed which was usually) 5000 characters per second, using a programmable comparator, and counted the matches. Looking at more general-purpose machines which were developed very shortly after the war, functionality like that would take something like 5 or 6 instructions per character, so I think it’s reasonable to think of a Colossus as running maybe 25 thousand instructions per second (compare with EDSAC or Baby, about five years later, running at 600 and 1100 instructions per second). However, it had essentially no memory (Baby had 1024 bits, EDSAC had a massive 9 kbits). Each Colossus, not counting the I/O (the bedstead and the printer), occupied perhaps a hundred cubic feet. So let us call it 10 kIPS/m^3.
RPi, in comparison is about 10 TIPS/m^3. So that’s nine orders of magnitude (unless I’ve dropped three or six somewhere). Of course, the instructions etc are quite different.

Googlefight, done.

http://www.googlefight.com/index.php?lang=en_GB&word1=raspberry+pi&word2=colossus

But in all seriousness I think a fairer comparison would be to produce a Pi using 1940s technology.

Colossus has some significant advantages over Arm11 – the systolic arrays, for instance. Although Arm11 has SIMD instructions, it lacks the same degree of parallelism. Since a part of the algorithm was limited by the physical speed of the tape (27 mph or 5000 Bps), they apparently ran Colossuses (Colossi?) in parallel, which should maybe be taken into account too. Is Colossus allowed to use a modern, stronger, faster tape? Are we allowed to overclock Colossus? :)

If the data quoted here: http://en.wikipedia.org/wiki/Colossus_computer (under ‘Reconstruction’) is true, the rebuilt Colossus is 240 times slower than a 2007 laptop clocked at 1.4 GHz.

A core 2 duo M runs at about 5379 Dhrystone MIPS ( http://www.roylongbottom.org.uk ). This isn’t the processor (since it wasn’t around in 2007) but let’s just say it’s roughly equivalent.

If Colossus is running at 1/240th that ‘speed’, it would be running at 23 MIPS.

An Arm1176 runs at about 965 Dhrystone MIPS ( http://www.arm.com/products/processors/classic/arm11/arm1176.php )

If we’re willing to cope with the huge number of assumptions and inaccuracies involved, that means that our eventual fag-packet number is that one Pi is roughly equal to 42 Colossi.

So the answer is 42. Now, the question… that’s a lot more difficult… we’d have to design a whole new computer for that :o)

Despite posting the above – comparing Colossus to anything is kind of heretical and I’m already feeling slightly guilty about posting MIPS for it. It’s like putting your grandmother on “Hot Or Not?”
So, sorry. :)

I think a “Like” button should be introduced to this page so people can show their appreciation for posts similar to Chris’ above.

Brilliant.

Can’t you get Mooncake to email Eben the details? :-)

It’s a great shame that those who restored Colossus could not be bothered to thank some of those who donated our rare tubes to the project, or even acknowledge their safe receipt.

Why not see how long the PI would take to crack the same codes as the Colossus did. This would be a true test, since the Colossus was only built to crack these codes. Did try and leave a comment on the Posterous but couldn’t. So I am leaving it here.

For those interested in early computers there is a project to rebuild EDSAC http://www.edsac.org/

It turns out that the difficult to obtain component is not the valves, which were made in large numbers and people kept spares as they failed periodically, but the valveholders, which did not fail often so spares were not kept. If anyone knows of a supply of EF54 valve holders please get in touch.

I just wanted to point out that the hashes for Debian “squeeze” and Arch Linux Arm are exactly identical. Is this correct? I don’t know if there is proper forum for this post.

“Colossus … was the first digital, electronic, programmable computer”
Not quite. It was not programmable in the sense that the program was stored within the device. The Princeton Institute for Advanced Study “IAC” machines (Johnniac, Maniac, Illiac, etc.) hold that distinction, which were largely based on the work on the University of Pennsylvania / U.S. Army ENIAC project in Philadelphia, Pennsylvania (later moved to the U.S. Army Aberdeen Proving Grounds in Aberdeen, Maryland).
In fact, it’s a stretch to call Colossus a computer at all, as the difference between a computer and anything else is that a computer can alter its execution path based on the results of previous computation (i.e., branching). Colossus only performed comparisons between arrays of characters, only then in a very specific way that was not easily alterable, and certainly not by any effort we would consider “programming”. Its output was basically a description of how well sets of characters matched each other, and it performed no other computation based on that description. Computing historians classify such machines as “reconfigurable”, not programmable, which also describes ENIAC, the Harvard Mark I through IV, and a number of early commercial data processing machines from IBM, Univac, etc. Charles Babbage’s Difference Engines were sophisticated mechanical calculators, not computers, but, if it had ever been built, his Analytical Engine would have been the world’s first mechanical digital computer, as it would have had memory, a central processing unit (including arithmetic and logic units), punched-card input for both data and programs, a printer/typesetter for output, and a bus tying everything together.
Although it didn’t achieve operational status beyond research and development (i.e., “operational” meaning being used to perform utilitarian functions), it’s now generally agreed that the Atanasoff-Berry Computer (ABC) at the University of Iowa may be the closest example of the earliest digital electronic computer, as it predated WW-II, and elements of that work influenced many other projects, most notably ENIAC and Colossus. At the same time, Konrad Zuse had developed the Z-1 through Z-3 binary digital computers (all other computers during this period were decimal, not binary) in his parents’ apartment in Berlin during WW-II, but, it was destroyed during a bombing. The common thread among all of these projects (except Zuse’s) was Hungarian-born Dr. John von Neumann, who was a mathematics professor at the IAS when Alan Turing earned his PhD there, and is namesake of the von Neumann architecture virtually all computers use today. This architecture was described in his “First Draft of a Report on the EDVAC” (EDVAC was to be a follow-on to ENIAC, and directly resulted in construction of the IAC machines, as well as EDSAC in the UK, etc.). BTW, the name of the architecture as “von Neumann” is something he opposed, as he stated that he was only documenting the work being done by many people on the teams in Philadelphia, Bletchley Park, Iowa City, etc.
Von Neumann was probably the only person who was personally and intimately aware of the technical details of all of these efforts, as well as the Manhattan Project to develop the first nuclear weapons at Los Alamos (he was one of only a handful of people allowed to travel to and from Los Alamos – almost all scientists and engineers sent there, and those who brought their families, were not allowed to leave until after the attacks on Hiroshima and Nagasaki).
Like all great things, success has many fathers and mothers, but, failure is always an orphan. That’s unfortunate, because we learn everything from failures – success is simply the result of having eventually overcome many, many failures. Nothing ever comes full-blown from the head of Zeus, and no great achievement has ever occurred on the first try.

Contact GCHQ – they should know how fast a Colossus is versus a modern machine and they have a smart historian. Tony Sale demonstrated rebuilt Colossus to me and others – wartime paper tape running at 5000 characters per second / 30 miles an hour – the world’s fastest paper tape reader then and possibly now – they tried running it at 60mph but were worried about what happened when it broke. [Unlike the wire based video recorder for the BBC – coper wire at more than 100 mph]. Original selenium used for optical reader. Given that Colossus needed about 10kW power input to work at all, then we have 2k Pi’s == 1 Colossus as a minimum.

Colossus/Raspberry Pi calculation? I’m not a smartypants. Since the Colossus was single application that’s the only thing that can be compared in the compute power category. Maybe a real smartypants will code Raspberry Pi to do Colossus’ job. Then they can be compared.