Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: smp question about kns, engine, and other program tasks-Mr Hyatt

Author: Robert Hyatt

Date: 18:10:00 12/01/01

Go up one level in this thread


On December 01, 2001 at 06:54:42, Slater Wold wrote:

>On November 30, 2001 at 23:32:40, Robert Hyatt wrote:
>
>>On November 30, 2001 at 12:18:20, Slater Wold wrote:
>>
>>>On November 30, 2001 at 11:59:01, Robert Hyatt wrote:
>>>
>>>>On November 30, 2001 at 02:31:18, Slater Wold wrote:
>>>>
>>>>>On November 29, 2001 at 21:21:33, K. Burcham wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>>Mr Hyatt. i have read the posts here about deep fritz and its kns increase with
>>>>>>two processors.
>>>>>>
>>>>>>from the info i have seen with my dual machine, i have become curious about
>>>>>>something. below are the examples with difference in hardware.
>>>>>>
>>>>>>program A on single processor 1500 mhz     1400 kns
>>>>>>program A on dual   processor 3000 mhz     2000 kns
>>>>>>
>>>>>>program B on single processor 1500 mhz     1400 kns
>>>>>>program B on dual   processor 3000 mhz     1400 to 1500 kns
>>>>>>
>>>>>>
>>>>>>my question is only about the chess software. not the hardware. not the ram.
>>>>>>not the hash.
>>>>>>
>>>>>>is it possible with these smp programs that something else going on in the chess
>>>>>>software, that you can comment on. in other words if this kns is accurate and a
>>>>>>true value (that deep fritz is giving us), then is it possible the program is
>>>>>>doing something else with this second processor that will not show a kns
>>>>>>increase but will add to its strength. the reason for this question is that when
>>>>>>i run task manager in windows 2000, it shows that the program is using the
>>>>>>second processor with deep fritz as much as my other smp programs (90 to 100%)
>>>>>>but it shows no increase in kns.
>>>>>>
>>>>>>kburcham
>>>>>
>>>>>No.  Because it's not solving the problem any quicker either.
>>>>
>>>>
>>>>For the record, if you run crafty, you will _always_ see both cpus running
>>>>at 100%.  But it is possible that one thread is in a spin-lock waiting on
>>>>the other to release something, or that one is spinning waiting on work.
>>>>
>>>>IE just because a cpu is busy doesn't mean it is busy doing something
>>>>_useful_.  :)
>>>
>>>Speaking of which, did you know Crafty reports the wrong CPU usage time in
>>>Windows?  It always says that I am using like 90% when task manager (along with
>>>other utilities) say it's using 100%.
>>>
>>
>>I have seen this, but since I don't run windows here, I have never been able
>>to track it down.  If you are interested, I can tell you how the timing stuff
>>works and perhaps get it right...
>
>Sure.  Send me an e-mail.  I'd do whatever I can.
>
>>
>>
>>
>>
>>>I also checked the memory paging in Crafty between 3xxMB ram and 7xxMB RAM.  I
>>>am guessing Crafty does the global lock, because it did extremly well.  Better
>>>than any others tested.
>>
>>
>>Not sure what you mean by "global lock"...
>
>Locking the memory.  I've seen a lot of SMP programs swap over a MB a sec
>because the memory is not being locked.  Almost a must in Windows 2000.
>
>Anyone who's interested, can run an SMP program on a Windows 2000 machine, and
>press ALT+TAB to go to another running program.  See how much memory Windows
>2000 swaps in order to do this.  At times it can be > 3MB/sec.  perfmon will
>report this.


I don't lock anything in my code, I simply malloc() a large chunk of memory
for the hash tables and go with it...



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.