Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: The art of debate

Author: Tom Kerrigan

Date: 19:38:40 01/27/00

Go up one level in this thread


On January 27, 2000 at 21:14:25, Robert Hyatt wrote:

>No... what I said was that I knew what Cray Blitz did internally, and how it
>worked.  And I was _still_ surprised by how much slower the PC would execute

Okay, if your only point was that you were surprised going from A to B, then
that's fine.

The reason for my "confusion" is a comment that you made a few posts ago:

>The point is on "what" architecture?  40K on a sparc == 20K on an X86.

And then you begin talking about how much you can do with Cray instructions. I'm
sure you can see why I might think your point was something else.

>What is the difference between 40K and 400K instructions?  Significant enough

I remember that MChess was running at ~2,500 NPS on a 133MHz Pentium in 1995.
133M / 40k = 3,300
Hsu's estimate implies that DB would run a little faster than MChess. If the
estimate is off by a factor of 2 either way, I don't think it makes a huge
difference. But if the estimate is "optimistic" by a factor of 10, that means DB
would search 250 NPS, which I don't consider reasonable for a chess program.

>>It doesn't matter HOW he thought he could compute the term, only only matters
>>that it's POSSIBLE.
>But it _does_ matter.  Otherwise how do you do the computation?  And are you
>thinking in terms of what is easy in hardware?  Have you ever written a piece
>of code, thinking when you started that it would be 2K lines of code, but ended
>up 20K?  I would never have guessed that Crafty would end up at nearly 50K and
>still growing.

But that argument goes both ways. I doubt that he would consistently
underestimate how much work it takes to evaluate every single term.

>Anything is possible.  I simply take that "number" as a "SWAG" to make a point
>that a _lot_ of things are going on inside DB's processor.  If _I_ had written
>that article, I would probably have guessed "low" to be conservative, since
>everyone seems to want to jump all over any significant claims he makes...

But there is another opposite argument here: he wants to make his chip seem as
cool as possible.

Until we know more, I don't see why we can't just assume that Hsu is right.
You're coming up with every reason for his estimate to be low, but I could be
arguing that his estimate is high just as aggressively. The point is, neither of
us seems to know anything besides the actual estimate, so I don't see why we
can't just take it on faith for now.

-Tom



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.