Why is MySQL nearly twice as fast on Linux?

[JG]

>
>once again, here's the deal.
>
>i'm willing to PAY someone to own this issue and figure out how to resolve
>it. also give them access to my box to do whatever they feel like (it
>needs to stay AMD64 - but i don't care if you go up to 5.3, down to
>5.2-current, 5.1, whatever)
>
>so i'm supplying resources and incentive. why is nobody stepping up to the
>plate to help figure out where the bottleneck is? it *sounds* like it's
>threading or the scheduler or a combination of both, i don't know.
>
>but i'm pledging at least $250 USD, and someone else will pledge another
>$100 - and that's just two of us.
>
>if someone owns it and can get a fix out in the next week or two (i don't
>care how or where) i could even give a bonus.
>
>once again - resources and incentive. let's figure this out so everyone
>can benefit. i just want to expedite this effort.

I'm the other $100 sponsor on this offer.... Mike sort of jumped the gun here,
but let me add that we want to see FreeBSD within +/- 10% performance Vs. 
"Stock"
Linux results with a comparable or equivalent my.cnf files

If it's possible, we'll pay to have it happen.