> I'm not sure whether you are familiar with Benchmark#bmbm which does a
> rehearsal - personally I rather not switch off GC since in realistic
> situations GC time belongs into the mix.  But results are rather
> similar:
Sure. GC does belong to the mix. Now, if GC is enabled you are not able to 
compare anything. Let's assume that GC runs during 'array init', you will 
say 'hey, struct init is faster'. Now, if GC runs during 'struct init' the 
result may change ...

Keeping GC is meaningful when benchmarking a whole application. In 
microbenchmarks like these, it is simply noise.
-- 
Sylvain Joyeux