ChessUSA.com TalkChess.com
Hosted by Your Move Chess & Games
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

cache alignment of tt
Post new topic    TalkChess.com Forum Index -> Computer Chess Club: Programming and Technical Discussions Flat
View previous topic :: View next topic  
Author Message
Daniel Shawul



Joined: 14 Mar 2006
Posts: 3051
Location: Ethiopia

PostPost subject: Re: cache alignment of tt    Posted: Mon Mar 12, 2012 4:49 am Reply to topic Reply with quote

I was actually looking at the post you made sometime back comparing tt probes with and without alignment.
I was comparing nps of a 18 ply search since I didn't have a profiler but now I did QueryPerformanceCounter() and got a tiny tiny speed up BUT it still is slower nps wise when I take out the timing routine which is actually what I saw before.

Query performance of hash_probe 3 runs each

Code:

No alignment:

microsecond/probe         NPS
209989                         999109
210978                         998072
210551                        1000685

Alignment

206678                        1002805
206402                        1001222
205490                        1003311


That gives an improvement of 0.2% if you average the three runs but without the timing routing
Code:

Without alignment
1275611
1275611

With alignment
1262112
1263824

Now the one without alignment is faster. And the behavior is pretty consistent. It is also better to compare overall behavior but I really don't have any idea what is changing when I force the alignment.

Anyway it is not a very good optimization.

cheers
_________________
https://sites.google.com/site/dshawul/
https://github.com/dshawul
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger
Display posts from previous:   
Subject Author Date/Time
cache alignment of tt Daniel Shawul Sun Mar 11, 2012 10:22 pm
      Re: cache alignment of tt H.G.Muller Sun Mar 11, 2012 10:39 pm
            Re: cache alignment of tt Daniel Shawul Sun Mar 11, 2012 11:06 pm
      Re: cache alignment of tt Jon Dart Mon Mar 12, 2012 12:43 am
            Re: cache alignment of tt Daniel Shawul Mon Mar 12, 2012 2:53 am
            Re: cache alignment of tt Vincent Diepeveen Thu Mar 15, 2012 8:12 pm
      Re: cache alignment of tt Robert Purves Mon Mar 12, 2012 4:10 am
            Re: cache alignment of tt Daniel Shawul Mon Mar 12, 2012 4:49 am
      Re: cache alignment of tt Robert Hyatt Mon Mar 12, 2012 5:21 am
            Re: cache alignment of tt Ricardo Barreira Mon Mar 12, 2012 8:25 am
                  Re: cache alignment of tt Robert Hyatt Mon Mar 12, 2012 3:54 pm
                        Re: cache alignment of tt Alvaro Cardoso Tue Mar 13, 2012 12:33 am
                              Re: cache alignment of tt Robert Hyatt Thu Mar 15, 2012 2:15 pm
                                    Re: cache alignment of tt Rémi Coulom Thu Mar 15, 2012 4:42 pm
                                          Re: cache alignment of tt Robert Hyatt Thu Mar 15, 2012 5:03 pm
                                                Re: cache alignment of tt Daniel Shawul Thu Mar 15, 2012 5:08 pm
            Re: cache alignment of tt Daniel Shawul Mon Mar 12, 2012 12:49 pm
Post new topic    TalkChess.com Forum Index -> Computer Chess Club: Programming and Technical Discussions

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




Powered by phpBB © 2001, 2005 phpBB Group
Enhanced with Moby Threads