Scala perf: Why is this Scala app 30x slower than the equivalent Java app?

Question

I am a very proficient C# developer, but need to start writing code that works on the JVM. The Java language is feature poor compared to C# these days, so I was interested in t

Answer 1

I've re-run your code (and increased number of cycles x1000, so to get some meaning into benchmark).

Results:

Scala: 92 ms
Java: 59 ms

You can see that Java is 30% faster.

Looking at the bytecode, I can say that two versions are almost identical - so the difference is really strange (the bytecode listing is quite long, so I won't post it here).

Increasing the count x10000 gives this:

Scala: 884 ms
Java: 588 ms

Since the results are fairly stable, there should be some constant factor lurking somewhere. Maybe in some parameters that "scala" runner passes to JVM?

EDIT:

My configuration:

$ java -version
java version "1.6.0_26"
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode)

$ scala -version
Scala code runner version 2.9.0.1 -- Copyright 2002-2011, LAMP/EPFL

$ inxi -SCD
System:    Host the-big-maker Kernel 2.6.35-22-generic x86_64 (64 bit) Distro Linux Mint 10 Julia
CPU:       Quad core AMD Phenom II X4 965 (-MCP-) cache 2048 KB flags (lm nx sse sse2 sse3 sse4a svm) 
           Clock Speeds: (1) 800.00 MHz (2) 800.00 MHz (3) 800.00 MHz (4) 800.00 MHz
Disks:     HDD Total Size: 750.2GB (5.8% used) 1: /dev/sda OCZ 90.0GB 
           2: /dev/sdb ST3500413AS 500.1GB 3: /dev/sdc ST3802110A 80.0GB 
           4: /dev/sdd Maxtor_6Y080M0 80.0GB