Ketil Malde wrote:

MR K P SCHUPKE writes:

<snip>

One would expect a lazy and pure language

Not lazy! See below.

to be excellent for parallelization, since the programmer is generally removed from the actual flow of execution anyway. At some point (for some n), being able to spawn n threads will gain you more than a factor c constant overhead, ^^^^^^^^^^^^^^^^^^^^^^^^^^

What makes you think the overhead is constant? Without Optimistic Evaluation, Haskell programs mutate /heavily/, and even with Optimistic Evaluation I'm sure there is some mutation going on. With a truly parallel system, every mutation has to be locked in some way; reducing the number of locking operations to merely constant overhead is an interesting (as in extremely difficult) research problem.

and Haskell programs, with a run-time system that can evaluate expressions in paralllel, will outperform single threaded C code.

(But it probably isn't that simple, or we would have it already :-)

Nope. Jon Cast