7-men Syzygy attempt

Discussion of chess software programming and technical issues.

Moderators: bob, hgm, Harvey Williamson

Forum rules
This textbox is used to restore diagrams posted with the [d] tag before the upgrade.
noobpwnftw
Posts: 362
Joined: Sun Nov 08, 2015 10:10 pm

Re: 7-men Syzygy attempt

Post by noobpwnftw » Fri May 04, 2018 4:30 pm

Sesse wrote:tablebase.sesse.net will also mirror, as soon as I can get everything downloaded and verified somehow (are there checksums anywhere?).
The syzygy file format embeds a checksum in each file, which can be checked with tbcheck program.

Sesse
Posts: 181
Joined: Mon Apr 30, 2018 9:51 pm
Contact:

Re: 7-men Syzygy attempt

Post by Sesse » Fri May 04, 2018 8:46 pm

All checked, now mirrored. 1.2 TB in all, I suppose more to come (although I don't have 35 TB of disk…). 10 Gbit/sec, northern Europe.

syzygy
Posts: 4458
Joined: Tue Feb 28, 2012 10:56 pm

Re: 7-men Syzygy attempt

Post by syzygy » Fri May 04, 2018 9:43 pm

Sesse wrote:All checked, now mirrored. 1.2 TB in all, I suppose more to come (although I don't have 35 TB of disk...). 10 Gbit/sec, northern Europe.
I expect it to be more like 20 TB (and approx 10+10 for WDL+DTZ). But I could be wrong - I don't even remember how I arrived at the estimate.

I didn't expect that all this data was going to be mirrored so generously :D

Sesse
Posts: 181
Joined: Mon Apr 30, 2018 9:51 pm
Contact:

Re: 7-men Syzygy attempt

Post by Sesse » Fri May 04, 2018 11:13 pm

My estimation was just wild extrapolation. People talked about 10 TB for WDL, and for the current generated 7-man TBs, DTZ files are about 2.6x the size of WDL.

User avatar
Nordlandia
Posts: 2477
Joined: Fri Sep 25, 2015 7:38 pm
Location: Sortland, Norway

Re: 7-men Syzygy attempt

Post by Nordlandia » Fri May 04, 2018 11:55 pm

Steinar H. Gunderson:

Imagine sesse probing 7-men syzygy, it will definitely be a big jump in analysis power. Do you plan/consider purchase SSDs large enough for probing 7-men WDL or multiple in raid 0?

I guess 7-men DTZ can be stored on HDD.

syzygy
Posts: 4458
Joined: Tue Feb 28, 2012 10:56 pm

Re: 7-men Syzygy attempt

Post by syzygy » Sat May 05, 2018 12:31 am

Sesse wrote:My estimation was just wild extrapolation. People talked about 10 TB for WDL, and for the current generated 7-man TBs, DTZ files are about 2.6x the size of WDL.
The pawn tables will probably take the ratio down.

For 5-piece tables, the ratios DTZ/WDL are:

Code: Select all

             WDL        DTZ       DTZ/WDL
pawnless   68132288   287321600    4.217
pawnful   326710624   297447328    0.910
total     394842912   584768928    1.481
For 6-piece tables:

Code: Select all

              WDL            DTZ      DTZ/WDL
pawnless   11896768096   30359010784   2.552
pawnful    60937299376   57032537776   0.936
total      72834067472   87391548560   1.200
Going from 5 to 6, WDL size multiplied by 184.5. To keep 7-piece WDL below 10TB, the factor needs to be just below 151 (I am counting 1kb = 1024 :)). But Lomonosov DTM size went up by a factor of about 150, I think, and WDL and DTZ should do better than that.

IQ
Posts: 161
Joined: Thu Dec 17, 2009 9:46 am

Re: 7-men Syzygy attempt

Post by IQ » Sat May 05, 2018 7:19 am

Lets just hope 7p WDL stay below 10TB - so they fit on one HD.

Sesse
Posts: 181
Joined: Mon Apr 30, 2018 9:51 pm
Contact:

Re: 7-men Syzygy attempt

Post by Sesse » Sat May 05, 2018 8:16 am

Nordlandia wrote:Imagine sesse probing 7-men syzygy, it will definitely be a big jump in analysis power. Do you plan/consider purchase SSDs large enough for probing 7-men WDL or multiple in raid 0?
I don't plan to buy 10 TB worth of SSD, no. I currently have two SSDs as cache in front of my RAID-6 array, which cache tablebases or whatever else the OS deems necessary. But of course, if the probing pattern is way spread out, they won't be helping any.

I don't know if anyone ever tried to quantify how many Elo each level of tablebases help? I seem to recall Vasik Rajlich said probing Nalimov bases in Rybka helped almost nothing (like, 1 Elo) over just using them at the root, but that's a long time ago.

Sesse
Posts: 181
Joined: Mon Apr 30, 2018 9:51 pm
Contact:

Re: 7-men Syzygy attempt

Post by Sesse » Sat May 05, 2018 8:18 am

syzygy wrote:I didn't expect that all this data was going to be mirrored so generously :D
Google evidently thought it should be mirrored some more, and Googlebot appeared at my doorstep to download tablebases… :-P

Now added robots.txt.

Jesse Gersenson
Posts: 575
Joined: Sat Aug 20, 2011 7:43 am
Contact:

Re: 7-men Syzygy attempt

Post by Jesse Gersenson » Fri May 11, 2018 7:23 pm

Sesse wrote:
Sat May 05, 2018 8:16 am
I don't know if anyone ever tried to quantify how many Elo each level of tablebases help? I seem to recall Vasik Rajlich said probing Nalimov bases in Rybka helped almost nothing (like, 1 Elo) over just using them at the root, but that's a long time ago.
A few years ago I was trying to get the 7-man tables built and Mark Lefler thought it'd be worth 'maybe 5 elo' but of course it needs to be tested, and there are multiple (hardware) factors which affect the performance.

LC zero recently had good success getting sponsorship for hardware.

How much would disks cost? I'd gladly donate money to help get you disks.

Post Reply