Quite interesting, but it seems they used the old Mono gc, when testing F# on linux

I tried to replicate their results (it wasn't really easy to setup, so I only ran few tests) to show the difference when using the SGEN gc, these are my results on my corei7 860 (4 cores + hyperthreading)

F# on Windows8 64bit (it should be .net 4.5)

.\fsharpbench.exe 80000 1 bharr 3

6.94s

F# on Linux (Mono 2.10.8)

mono-sgen Main.exe 80000 1 bharr 3

13.69s

mono Main.exe 80000 1 bharr 3

20.54s

and, by changing the gc's write barrier, you can shave off an half second more:

env MONO_GC_PARAMS="wbarrier=remset" mono-sgen Main.exe 80000 1 bharr 3

13.02s

Linux Scala 2.10M7

scalac-2.10 bh-impure.scala

scala-2.10 Simulation 80000 True 1

5.641 s

Scala 2.9

scalac bh-impure.scala

scala Simulation 80000 True 1

7.676 s

so, F# on Linux is still slower than Scala and F# on Windows, but the situation is not as bad as in the paper (4/5 times slower, or worse): it's in the same ballpark (a little more than 0.5 the speed on Windows) imho: definitely usable (on single core loads it is also much more competitive, from the few lines of F# that I've written)

btw: it seems also that Scala2.10 is quite faster than Scala2.9 :D