It's safe to assume that people complaining about a language's performance deal with CPU bound cases.
This is false: http://benchmarksgame.alioth.debian.org/u64q/benchmark.php?t...
That's a very unlikely assumption – many people will complain about the language before even profiling their code. I've seen people do things like complain about Python's performance before, say, realizing that they were making thousands of database queries or allocating a complex object inside an inner loop. Because they've heard “The GIL makes Python slow” it's incredibly common for even fairly experienced programmers to simply assume that they can't make their program faster without rewriting it in C and they never actually confirm that assumption.
> This is false: http://benchmarksgame.alioth.debian.org/u64q/benchmark.php?t....
That's a micro-benchmark collection. It's interesting for low-level performance but it doesn't tell you much about the kind of programs most programmers write. For example, I serve a lot of images derivatives over HTTP – it's certain that are many operations which could be significantly faster if they were written in C (i.e. reading HTTP headers in place rather than decoding them into string instances) but in practice none of that matters because almost all of the total runtime is already spent in a C library.
No, it's a meagre dozen "toy programs". (See Hennessy and Patterson "Computer Architecture").
> ... many operations which could be significantly faster if they were written in C ... none of that matters because almost all of the total runtime is already spent in a C library. <
See Sawzall quote -- http://benchmarksgame.alioth.debian.org/dont-jump-to-conclus...
Agreed – my point was simply that over a couple decades I've only seen a handful of cases where a performance issue which was due to the language rather than the algorithm or simple data volume. Such problems exist but not for the majority of working programmers.
Not in my experience. I've seen countless cases where people just assume they have a CPU bound bottleneck, but profiling reveals that it is actually IO bound.
And that's ignoring all the cases where people rewrite their code in a new language to get a 10 time performance boost, ignoring the fact that a better choice of algorithm and data structure would give them a 100 time performance boost.
This is false:
benchamarksgame doesn't come even close to cover what I'd consider "most cases" of programs written.
Is Python slower than C? In some cases YES. Is Python a slow language? NO, not always. Do I think that titles like "Why Python is slow" are misleading? YES, because are too generic, and give the wrong kind of idea.
Speed, as scalability or a lot of other concepts, are WAY more a problem of architecture and design than language. This doesn't mean that languages are irrelevant, but their importance in the achievement (or failure) of those goals is largely overstated.