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Up Topic Rybka Support & Discussion / Rybka Support / Hash File and/or Persistent Hash File??
- - By alistair [us] Date 2010-06-03 03:42
Hi All

Another Rybka engine optimisation question.

When is it good to use a hash file? Do you use a hash file only if you don't have much physical memory, in the same way that windows uses file swapping. Or is it is good to use a hash file as well as using physical memory, does this improve game analysis even more?

This leads to my next question, when would you use a persistent hash file, is this an extension of the hash file? I'm interested in why Rybka 3 has persistent Hash settings where Rybka 4 doesn't, why?

Also what is the MultiPV_cp setting in the engine settings? Is this related to the hash file? And why is it set higher in Rybka 3 than in Rybka 4?

Thanks

Al Nicholls
Parent - - By Uly (Gold) [mx] Date 2010-06-03 08:25

> When is it good to use a hash file?


When you have to unload Rybka or reboot, and you want to continue analysis where you left it.

> why Rybka 3 has persistent Hash settings where Rybka 4 doesn't, why?


The feature is no longer supported, so the recommendation is that you never use it for Rybka 3.

> Also what is the MultiPV_cp setting in the engine settings?


To make Rybka show less lines in MultiPV than you tell her, if they're bad.

> Is this related to the hash file?


No.

>And why is it set higher in Rybka 3 than in Rybka 4?


Because it was causing overflow in some interfaces. In practice it makes no difference.
Parent - - By cma6 (****) Date 2010-06-03 19:10
Vytron, what about the engine parameter "MultiPV" with default value? What does that do?
                 Thanks, CMA
Parent - By keoki010 (Silver) [us] Date 2010-06-03 19:58
Leave it at the default. It controls how many pv lines you can display.
Parent - By alistair [us] Date 2010-06-03 21:07
Thanks heaps Vytron, good to know!
Up Topic Rybka Support & Discussion / Rybka Support / Hash File and/or Persistent Hash File??

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