Hello Simon, Thanks for your suggestion (I didn't know about this option) On Monday 12 Sep 2005 12:04 pm, Simon Marlow wrote:
On 05 September 2005 19:38, Adrian Hey wrote:
On Monday 05 Sep 2005 5:42 pm, Jan-Willem Maessen wrote:
This agrees with my theory.
Thanks, I'm sure this must be the explanation. I guess the moral of the story is that for comparative benchmarks you really do need to make sure you're comparing like with like. Very small differences in test method can have a significant impact on running time it seems.
Can you confirm the hypotheses by inspecting the output from +RTS -sstderr, which tells you the breakdown of GC vs. mutator time?
OK, I've done the tests and they do seem to confirm this, but they're a bit misleading because the figures presumably include time and energy spent calculating the test data too, which is non-trival. (the Insertion times reported do not include test data calculation). --------------- Non-cumulative ------------- InsertTime = 280.0 1,061,418,244 bytes allocated in the heap 342,983,048 bytes copied during GC 24,097,548 bytes maximum residency (16 sample(s)) 3652 collections in generation 0 ( 3.90s) 16 collections in generation 1 ( 2.98s) 62 Mb total memory in use INIT time 0.00s ( 0.00s elapsed) MUT time 10.73s ( 10.74s elapsed) GC time 6.88s ( 7.01s elapsed) EXIT time 0.00s ( 0.00s elapsed) Total time 17.61s ( 17.75s elapsed) %GC time 39.1% (39.5% elapsed) Alloc rate 98,920,619 bytes per MUT second Productivity 60.9% of total user, 60.5% of total elapsed --------------- Cumulative ------------- InsertTime = 775.0 1,068,399,252 bytes allocated in the heap 546,486,356 bytes copied during GC 23,234,404 bytes maximum residency (20 sample(s)) 3679 collections in generation 0 ( 6.89s) 20 collections in generation 1 ( 4.33s) 61 Mb total memory in use INIT time 0.00s ( 0.00s elapsed) MUT time 11.89s ( 11.93s elapsed) GC time 11.22s ( 11.34s elapsed) EXIT time 0.00s ( 0.00s elapsed) Total time 23.11s ( 23.27s elapsed) %GC time 48.6% (48.7% elapsed) Alloc rate 89,856,959 bytes per MUT second Productivity 51.4% of total user, 51.1% of total elapsed Regards -- Adrian Hey