Author: Heiner Marxen
Date: 07:30:09 01/28/02
Go up one level in this thread
On January 27, 2002 at 17:06:42, leonid wrote: >On January 27, 2002 at 09:02:31, Heiner Marxen wrote: > >>On January 26, 2002 at 07:11:47, leonid wrote: >> >>>Hi! >>> >>>This position is one between few hundereds that was created long time ago (June >>>2001) and never came here. Mate is very moderate and it will take not big effort >>>to solve it. >>> >>>[D]1q1kq1q1/qQrbbrQq/3QQ3/NqQqqQqN/8/BnR2RnB/3PP3/3K4 w - - >>> >>>Please indicate your result. >>> >>>Thanks, >>>Leonid. >> >>Since black is threatening Qgxd2# the search tree is small. Chest on an >>Athlon 1500+ needs just 154 second (2.6 minutes) to find a unique solution >>for mate in 9 (128 MB hash): >> >>PV: Qdxe7+ Qexe7 Qcxe7+ Qxe7 Bxe7+ Rxe7 Qff8+ Qxf8 Rxf8+ Re8 Rxe8+ Bxe8 Qec8+ >>Qxc8 Qxc8+ Rxc8 Rxc8# >> >>Timing and EBF: >># 3 0.01s 1kN [ 13.35] 0.95 94- 0 >># 4 0.06s [ 6.00] 10kN [ 7.28] 1.16 420- 0 >># 5 0.33s [ 5.50] 56kN [ 5.63] 1.49 2267- 0 >># 6 1.59s [ 4.82] 264kN [ 4.72] 1.94 11724- 0 >># 7 6.92s [ 4.35] 1115kN [ 4.23] 2.56 57089- 0 >># 8 30.50s [ 4.41] 4626kN [ 4.15] 3.26 268493- 0 >># 9 154.58s [ 5.07] 22281kN [ 4.82] 3.86 1582341- 4173 > > >Hi, Heiner! > >Probably no other program, beyond your, can even try this position by brute >force. > >I actually don't know exactly my time for 9 moves for brute force. I see only >search done by brute force in June 25. Later my program was changed. In June >time was: > >Move Time Branching factor NPS. > >4 0.71 sec 212k > 6.92 >5 4.94 sec 142k > 5.87 >6 29 sec 117k > 5.98 >7 2 min 53 sec 91k > 5.46 >8 15 min 46 sec 84k > >Mate in 9 moves was found by selective. > >Seeing your time is always interesting. It indicate, at least to me, that on >this position mine (if used all advances that you already have in your 3 ply) >solver could be speeded as much as 30 times. Around 10 times when I look speed >for 4 ply, and other 3 because of Assembler. Please note that I used faster hardware than usual. That were an Athlon with 1.5 GHz as opposed to the Athlon with 600 MHz I normally use. May be you missed this factor 2.5 :-) Chest is still faster :-) Cheers, Heiner
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