Hi Greg
Anyone have an explaination for the 2x speed increase for running Kevin's version with '+RTS -G1'?
+RTS -Sstderr -RTS and +RTS -sstderr -RTS will probably indicate why. I'd be surprised if the amount of data copied for the semi-space collector isn't much less than for the generational. Chances are that data is dying off very quickly and very little is being copied for the semi-space collector - the allocation area has a variable sizing policy and this size of allocation area is sufficient for the majority of the data to die off before it is filled and a GC kicks in - hence very little is copied. However, for the generational collector, the nursery is of fixed size. Here, the lifetime of the data is probably longer than the time it takes for the nursery to be filled and a minor GC kicks in and the data promoted to generation 1 (hence copied) where it then probably dies off but can't be collected until a major collection kicks in. Probably, or something like that ;-) Cheers Andy ********************************************************************* * Andrew Cheadle email: a.cheadle@doc.ic.ac.uk * * Department of Computing http://www.doc.ic.ac.uk/~amc4/ * * Imperial College * * University of London * *********************************************************************