Wikipedia:Reference desk/Archives/Computing/2016 April 15

= April 15 =

Most powerful
Whats the most powerful computer ever built?--178.99.232.11 (talk) 00:08, 15 April 2016 (UTC)
 * That depends on how you define "powerful" and "computer". Wikipedia has an article titled supercomputer where you can start your research to answer your question.  -- Jayron 32 00:10, 15 April 2016 (UTC)
 * Or the answer is Earth, as provided by Deep Thought. --Stephan Schulz (talk) 12:01, 15 April 2016 (UTC)
 * For an answer making rather standard assumptions about what counts as a single computer, see also TOP500. -- 160.129.138.186 (talk) 19:14, 15 April 2016 (UTC)


 * The real problem here (as suggested by Jayron) is in defining what a single computer is. Most "supercomputers" are just very large collections of rather standard computers...and if a "large collection of computers" counts then you have to treat giant server farms such as are owned by the likes of Google and Amazon as "supercomputers"...and then you have to ask: "How tightly interconnected do the individual computers have to be to count as 'a supercomputer'?" - if the answer is that they have to be on the same circuit board - you get a very different answer than if they are interconnected with high speed networking such as in a server farm - and if you allow the server farm then perhaps the answer to your question is "The Internet" - which is a very VERY large collection of computers.
 * On the other hand, if you go the other way and say "The most powerful computer on a single chip" then you have to ask yourself whether you allow multicore computer chips to count as a single computer - or whether each core has to be considered separately.
 * Then you get into tougher realms because GPU-based computing is now common and in that case there are hundreds of separate teeny-tiny computers on a chip - but they aren't really complete computers because they are typically in a SIMD array where all of the individual computers run the exact same instructions in the exact same order - albeit with different data. SIMD computers can calculate immense amounts of stuff in a short amount of time - but only if you need it done in parallel.  So a GPU can factor prime numbers massively quickly - but can't run a more typical application program using more than one of it's hundreds of cores.  So here you have machines that are massively powerful for some tasks and somewhat underpowered for others.  That's why machines like Google's "AlphaGo" Go playing machine have a mix of CPU and GPU 'computers' in the same 'super-computer'.
 * Then we have to consider storage and disk space. IBM's "Watson" (the computer that beat the very best humans at Jeopardy!) didn't have much in the way of large numbers of CPU's (well, not compared to most other supercomputers) - but it had enough high speed RAM memory to hold all of Wikipedia, all of IMDB and a bunch of other large "knowledge" sources.  The speed and accessibility of it's memory was what made Watson powerful - but what makes AlphaGo powerful is the banks of CPU's and GPU's.  Each is an exceedingly powerful computer - but in very different fields.  Watson would suck at playing Go and AlphaGo wouldn't stand a chance at Jeopardy! - they're meant for different things.   Then we can look at "Deep Blue" (the IBM computer that beat the best humans at chess) - and it has custom circuitry for doing chess calculations.  Applying it's power to ANY other problem would reveal a very "ordinary" looking computer with a large quantity of entirely useless circuitry!
 * Years ago, before the rise of networking and cheap commodity hardware - there were easy, unambiguous answers (generally with the word "Cray" in their names!)...but things got more complicated since then.
 * So - I don't know the answer here. I suspect that any "real" answer needs to be couched in a lot of if's, but's and maybe's.
 * SteveBaker (talk) 17:33, 15 April 2016 (UTC)


 * Most powerful is obviously something like a TRS-80 or C=64. I could easily smash the hell out of Watson with a sturdy old C=64. Toss in a 1540 drive with that thick cable and I can get that swinging and fend off the IBM programmers as well. What could be more powerful? (Seriously - just surprised nobody gave a completely obnoxious example of what "powerful" could mean. It is Friday!) 209.149.113.15 (talk) 17:54, 15 April 2016 (UTC)