[Haskell-cafe] Parallel weirdness

[Jake Mcarthur]

On Apr 19, 2008, at 9:56 AM, Andrew Coppin wrote:
> Weird thing #3: Adding the "-threaded" compiler option makes  
> *everything* run a few percent faster. Even with only 1 OS thread.

I had a similar thing happen to me once. (http://geekrant.wordpress.com/2007/11/29/holy-shmoly-ghc-does-some-magic-all-by-itself/ 
) It bothered me at the time, but as Simon Marlow said in the comments:

> I wouldn’t believe these figures too much. I couldn’t repeat the  
> same effects here, but since this is such a tiny fragment of code,  
> small effects are magnified, and differences can sometimes appear  
> and disappear depending the day of the week.

- Jake McArthur