![[gb]](/mwf/v12/flags/gb.png "United Kingdom")
Hi.
I'm analysing games on a quad-core system with my copy of DR 3.
I use it to search games for top 4 matches within a 30 second time-frame at a minimum depth = 12, max depth = 20 with the hash set to 256Mb.
Using this engine I'm generally only getting to depth = 12-14 for most positions and Rybka seems to take forever to finish analysing some of the lines.
Can someone please explain to me why DR3 only reaches depth = 13 when under the same settings Stockfish 1.8 x64 JA gets to depth = 18 or 19 & also doesn't tend to hang, causing analysis to be delayed?
Sorry if this has been covered before, but any explanation is gratefully received.
I'm analysing games on a quad-core system with my copy of DR 3.
I use it to search games for top 4 matches within a 30 second time-frame at a minimum depth = 12, max depth = 20 with the hash set to 256Mb.
Using this engine I'm generally only getting to depth = 12-14 for most positions and Rybka seems to take forever to finish analysing some of the lines.
Can someone please explain to me why DR3 only reaches depth = 13 when under the same settings Stockfish 1.8 x64 JA gets to depth = 18 or 19 & also doesn't tend to hang, causing analysis to be delayed?
Sorry if this has been covered before, but any explanation is gratefully received.
![[de]](/mwf/v12/flags/de.png "Germany")
depth and nodes are quite different for different engines and different positions. hanging can be caused by "fail lows" or "fail highs", when the engine sees a better move and starts to search it to the same depth as the previous main line
A-ha!:
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http://www.rybkachess.com/index.php?auswahl=Rybka+3+FAQ
Rybka 3 FAQ
...
Technical
The kn/s for Rybka 3 are roughly half the kn/s for Rybka 2.3.2a. Is everything ok with my machine?
Yes. This is the expected difference.
Rybka 3 seems to take much longer to reach a given depth than Rybka 2.3.2a using infinite analysis in the ChessBase GUI. Example: R2.3.2a-64 was reaching 16 ply depth in 1 min 20 sec - R3 taking 10 minutes to reach same depth and same hardware (Q6600). Is this normal?
Yes. This is normal and expected. Rybka 3 has a different search, with a higher branching factor. The overall search efficiency of Rybka 3 is of course better.
What is the effective speedup for Rybka 3 when running on a multi-processor platform?
We'll post these figures as soon as they are available.
If Rybka 2.3.2a searches for 3 minutes and reports a depth of 19, while Rybka 3 searches for 3 minutes and reports a depth of 18, does this mean that Rybka 2.3.2a has looked into the position to a greater depth, and therefore must be "seeing" more by looking deeper (even though the breadth may be lesser)?
No, not at all. The depth is just a number Rybka uses to keep track of her search. It does not indicate any breadth vs depth tradeoff or anything else which might be meaningful to the user. All you can say is that depth X+1 for Rybka 3 is deeper than depth X for Rybka 3.
Are Rybka's node counts on multi-processor machines literal?
No. They are adjusted for the estimated multi-processor efficiency so that they can be used to compare Rybka performance on machines with different numbers of cores.
Rybka's kn/s figure doesn't increase much when she runs on machines with more processors, compared to other programs. Does this mean that she scales worse on such hardware?
No. Rybka's kn/s on multi-processor machines reflects the estimated multi-processor efficiency, so that her kn/s figures provides a true speedup. Other engines typically display literal node counts, which include many "wasted" nodes, and this can give a false impression of a better multi-processor scaling.
Has Rybka been slowed down to prevent decompilation?
No. We have a much better way to deal with this issue - just wait a bit and you'll see :) .
What is the improvement in playing strength compared to previous Rybka versions?
We'll post these figures as soon as they are available.
*********
Does anyone now know the figures referred to in bold?
***********
http://www.rybkachess.com/index.php?auswahl=Rybka+3+FAQ
Rybka 3 FAQ
...
Technical
The kn/s for Rybka 3 are roughly half the kn/s for Rybka 2.3.2a. Is everything ok with my machine?
Yes. This is the expected difference.
Rybka 3 seems to take much longer to reach a given depth than Rybka 2.3.2a using infinite analysis in the ChessBase GUI. Example: R2.3.2a-64 was reaching 16 ply depth in 1 min 20 sec - R3 taking 10 minutes to reach same depth and same hardware (Q6600). Is this normal?
Yes. This is normal and expected. Rybka 3 has a different search, with a higher branching factor. The overall search efficiency of Rybka 3 is of course better.
What is the effective speedup for Rybka 3 when running on a multi-processor platform?
We'll post these figures as soon as they are available.
If Rybka 2.3.2a searches for 3 minutes and reports a depth of 19, while Rybka 3 searches for 3 minutes and reports a depth of 18, does this mean that Rybka 2.3.2a has looked into the position to a greater depth, and therefore must be "seeing" more by looking deeper (even though the breadth may be lesser)?
No, not at all. The depth is just a number Rybka uses to keep track of her search. It does not indicate any breadth vs depth tradeoff or anything else which might be meaningful to the user. All you can say is that depth X+1 for Rybka 3 is deeper than depth X for Rybka 3.
Are Rybka's node counts on multi-processor machines literal?
No. They are adjusted for the estimated multi-processor efficiency so that they can be used to compare Rybka performance on machines with different numbers of cores.
Rybka's kn/s figure doesn't increase much when she runs on machines with more processors, compared to other programs. Does this mean that she scales worse on such hardware?
No. Rybka's kn/s on multi-processor machines reflects the estimated multi-processor efficiency, so that her kn/s figures provides a true speedup. Other engines typically display literal node counts, which include many "wasted" nodes, and this can give a false impression of a better multi-processor scaling.
Has Rybka been slowed down to prevent decompilation?
No. We have a much better way to deal with this issue - just wait a bit and you'll see :) .
What is the improvement in playing strength compared to previous Rybka versions?
We'll post these figures as soon as they are available.
*********
Does anyone now know the figures referred to in bold?
You can find playing strengt figures when clicking on the "independent testing" links on the right side of our website: http://rybkachess.com/
About the speedup: this is a bit difficult to say, but I assume there are some figures somewhere in the forum. Maybe Vas shouldn't have promised to post figures :)
About the speedup: this is a bit difficult to say, but I assume there are some figures somewhere in the forum. Maybe Vas shouldn't have promised to post figures :)
Cheers Felix.
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