[mateuszf]

In fact JVM is pretty fast. If you run a simple java app without dependencies and only displaying "Hello world" it will run in about 1s on modern hardware. The problem with Clojure is AFAIR related to parsing and loading a big number of namespaces which is quite slow.

[fijal]

1s to print hello world is an awful lot I would like to point out.

[potatosareok]

Upvoted you because I agree. JVM has many strong points but I don't think anyone is disputing that startup time is a weakness. I've used some java tools that you invoke from a command line and I'm always slightly annoyed by how slow they are.

As an aside - I was trying to reduce -Xmx to improve HelloWorld startup (lol idk...) and Xmx smaller then 1024k and it couldn't start up with less then 1024k so there's that.

On my windows computer (also I barely know what I'm doing so probably even timing it wrong).

  [Mon Mar 09 03:22:31 zebra@ZEBRA:~ ]
  $ time a.exe
  Hello, world
  real    0m0.098s
  user    0m0.015s
  sys     0m0.015s
  [Mon Mar 09 03:22:34 zebra@ZEBRA:~ ]
  $ time java Hello
  Hello, world!

  real    0m0.285s
  user    0m0.000s
  sys     0m0.031s

[unstabilo]

Hello World execution time benchmark in many languages:

http://lists.nongnu.org/archive/html/chicken-users/2011-03/m...

With Haskell:

http://lists.nongnu.org/archive/html/chicken-users/2011-03/m...

[lmm]

Worry about -Xms rather than -Xmx for startup times.

I suspect there are ways to make it faster (e.g. there's a nashorn runner that starts up appreciably faster than "proper" java), but the main use case for java is server-side programs that run for days or weeks between restarts, so it's optimized for that use case.

[kyllo]

the main use case for java is server-side programs that run for days or weeks between restarts, so it's optimized for that use case.

Unfortunately for the folks who still have to use Java desktop software written in Swing.

[mateuszf]

Sure it's a lot, but clojure startup times are significantly longer than that.

[ajuc]

> If you run a simple java app without dependencies and only displaying "Hello world" it will run in about 1s on modern hardware.

> time for x in $(seq 1 100); do ./helloworld.py ; done

    real    0m1.240s
    user    0m0.902s
    sys     0m0.343s

That's reasonably fast.

Java for comparison:

> time for x in $(seq 1 100); do java Hw; done

    real    0m4.952s
    user    0m4.051s
    sys     0m1.071s

And I had to compile java first. Still, I expected worse from java TBH.

[virmundi]

Out of curiosity which Java? OpenJDK or Oracle or IBM?

[ajuc]

     > java -version
     java version "1.7.0_72"
     Java(TM) SE Runtime Environment (build 1.7.0_72-b14)
     Java HotSpot(TM) 64-Bit Server VM (build 24.72-b04, mixed mode)

[virmundi]

Thanks. I would have figured hot spot to be better.

[pron]

You mean 60-80ms. Not 1s. Try it.