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Subject: Re: Zappa scaling #s

Author: Robert Hyatt

Date: 21:04:57 08/23/05

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On August 23, 2005 at 22:47:07, A. Cozzie wrote:

>Bob let me run on his 8-way from AMD for an hour or so tonight, so I thought I'd
>post the results.  I think he is going to run Crafty on these positions as well.
> This is only 3 positions so it doesn't represent anything statistically
>significant, but it gives me a general idea of how I'm doing.
>
>Nolot 1:
>
>1. Ng4xh6 c4-c3 2. Nh6-f5 c3xb2 3. Qd1-g4 Bb7-c8 4. Nf5xg7 Re6-g6 5. Qg4xg6
>Qe8xg6 6. Rg3xg6 Bf8xg7 7. Ne4xd6 Bc8-d7
> = (-0.13)      Depth: 14/40    00:03:27.46     889946kN (4290 KN/s, 28617
>splits, 1805 aborts)
>1. Ng4xh6 c4-c3 2. Nh6-f5 c3xb2 3. Qd1-g4 Bb7-c8 4. Nf5xg7 Re6-g6 5. Qg4xg6
>Qe8xg6 6. Rg3xg6 Bf8xg7 7. Ne4xd6 Bc8-d7
> = (-0.13)      Depth: 14/38    00:24:01.14     797115kN (553 KN/s, 0 splits, 0
>aborts)

My data:-------------------------------------------
log.001:      time=11:12  mat=-1  n=1288218287  fh=92%  nps=1.92M
log.002       time=2:05  mat=-1  n=1814283125  fh=91%  nps=14.51M

I get 7.56 NPS scaling, SMP speedup is 5.4X


>
>Larsen-Spassky:
>
>1... h5-h4 2. Be2xg4 Bf5xg4 3. h3xg4 h4xg3 4. Rh1-g1 Rh8-h2 5. Qc2-c3 Qe7-h4 6.
>Ke1-d1 Rh2-h1 7. Rg1xh1 Qh4xh1 8. Kd1-c2 g3-g2 9. Nb1-a3
> = (2.57)       Depth: 15/40    00:02:00.34     604796kN (5026 KN/s, 25748
>splits, 1329 aborts)
>1... h5-h4 2. Be2xg4 Bf5xg4 3. h3xg4 h4xg3 4. Rh1-g1 Rh8-h2 5. Qc2-c3 Qe7-h4 6.
>Ke1-d1 Rh2-h1 7. Rg1xh1 Qh4xh1 8. Kd1-c2 g3-g2 9. Nb1-a3
> = (2.57)       Depth: 15/42    00:12:46.15     500809kN (654 KN/s, 0 splits, 0
>aborts)
>
>Nolot 10
>
>1. Rf1xf7 Rf8xf7 2. Bd5xf7 Kg8xf7 3. Qd1-h5 Kf7-g8 4. Qh5-e8 Be7-f8 5. Nc3-d5
>Qb6xd4 6. Nd5-e7 Kg8-h8 7. Ra1-f1 Qd4-f6 8. Rf1xf6 g7xf6 9. Ne7xc8
> = (1.58)       Depth: 14/42    00:02:20.42     715711kN (5097 KN/s, 26886
>splits, 1288 aborts)
>1. Rf1xf7 Rf8xf7 2. Bd5xf7 Kg8xf7 3. Qd1-h5 Kf7-g8 4. Qh5-e8 Be7-f8 5. Nc3-d5
>Qb6xd4 6. Nd5-e7 Kg8-h8 7. Ra1-f1 Qd4-f6 8. Rf1xf6 g7xf6 9. Ne7xc8
> = (1.58)       Depth: 14/39    00:09:09.82     373351kN (679 KN/s, 0 splits, 0
>aborts)
>
>Scaling: 7.75, 7.68, 7.51, for an average of ~7.6
>Speedup: 6.94, 6.37, 3.91, fo an average of 5 or so.
>
>The first two are more or less standard positions and Zappa gets a speedup of
>6.5  The last is more or less the worst case as Zappa switches among mainlines
>constantly and evidentially some real wasted work was done :(
>
>Of course in a game things work a bit better as you ahve filled hash tables, but
>I'm still sort of disappointed.  The biggest problem I have is that the worst
>case is also the most important case: when you don't know what move to play :)
>
>anthony


I will run the other two tomorrow.  The last one is a bad (good) case for me.
At depth 13, the one processor test finds Rxf7 is just a tad better than Bb3,
but then Rf7 fails low at depth=14 and the search takes a long time to work its
way back to Bb3.  The parallel search doesn't fall for Rf7 at depth 13 due to
some sort of parallel search / hashing interaction.  As a result, my speedup on
this position is way over 8.0, which is an anomaly, called a "super-linear
speedup".  Something that happens here and there but not regularly...




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