Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Tip: how to reduce hard drive churning with tablebases

Author: William Penn

Date: 08:30:44 03/09/04

Go up one level in this thread


On March 09, 2004 at 05:28:30, Albert Bertilsson wrote:

>I'd just like to make one thing clear, the "churning" of the harddrive(s) is
>there because of the usage of tablebases. There is nothing that can solve this,
>having larger cache for tablebases help very little because the tablebases are
>so huge and you computer search very fast. Using faster drives (like scsi) will
>increase performance because of faster tablebase access times, but the drives
>will be working constantly at peek anyway. Turn of tablebases or get used to
>drive "churning", that is you options.

There is another option! Reduce hash table size. Then the engine speed returns
to near normal. True, it doesn't seem to affect the churning, but the engine
then runs at near normal speed - which is an important improvement.

>Using tablesbases give you perfect solutions to some positions but the obvious
>trade of is nps, I guess that many systems don't benefit very much from
>tablebases due to the reduced search speed.

Again, reducing hash table size tends to keep nps near normal speed, in my
experience with a souped-up Compaq Presario/XP 2400+/1G RAM running Windows XP
Home. I imagine that most systems can use tablebases OK if that is done. The
problem is that most people want to use as big a hash size as possible, but that
incorrect when the endgame approaches and tablebase access starts to be
significant - reducing the engine speed greatly.

>If you get a lot of harddrive noise you could try mounting your drive in some
>rubber bands instead of directly in the chassi to reduce the noise a little.

I'm not concerned about the noise. My Maxtor drives have a "quiet" mode
available if I want to use it. But it slows down access somewhat, and the noise
is also a good indicator of what the drive is doing, so I don't mind the little
extra noise.

>/Albert

Overall, you should be aware that such extreme hard drive churning will reduce
the lifetime of the drive significantly. Hard drives have a finite lifetime, and
can only seek so many times before the heads wear out eventually. Those who
write the code for chess tablebase access should keep this in mind, and do
whatever is necessary to improve it, and reduce the hard drive churning as much
as possible. There is really not much point to adding 6-man tablebases to most
ordinary computer systems until this churning problem is solved.
WP



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.