> On Mon, 2008-08-11 at 20:39 -0700, David Fotland wrote:
>> Uct also has the advantage that it is much easier to use with multiple
>> CPUs.  I know parallel alpha-beta exists, but my evaluation function is
>> not designed to be thread safe.  If I put a big lock around it, there
>> will be almost no SMP scaling, since almost all the time is in the
>> evaluation, not in the search.
>
> This is not the case with alpha-beta.  With additional processors,
> alpha-beta always does wasted work, and the more processors the more
> wasted work.  It still always benefits from additional CPU's.

I don't see how anything you said relates to what David said.

Aside from that, it's not theorethically necessary for alpha-beta to do
wasted work (although it will in practise), and more CPUs can make the
program worse on any practical architecture (mostly due to locking and
memory bandwidth).

I think any argument which is based on a state-of-the-art alpha-beta
searcher being different from a state-of-the-art UCT searcher will run
into severe problems sooner rather than later.

-- 
GCP
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