syzygy wrote:diep wrote:If you ever want a chance for having 7 men - storing more than win/draw/loss is gonna be a problem.
With current hardware 7-piece tables are just too big to handle in any reasonable way, let alone to use them during search. When I can generate them in RAM, I will start to get interested.
The 5 men are not interesting to get real small. Getting the 6 men in a few gigabytes is more interesting.
You have to start somewhere... If you can't compress the 5-piece, it might be hard to compress the 6-piece.
I will generate the 6-piece tables soon. I first need a bigger machine. Based on the ratio for Nalimov tables (I think 7 GB for 5, 1200 GB for 6), a reasonable estimate for my 6-piece WDL50+ tables would be 75GB. That's probably too pessimistic, since WDL should not increase as much in size when going to 6-piece as DTM. In any case, on a big enough machine most of it will fit in RAM.
I disagree. Supercompressed 7 men will be really compressing better than 6 men. Not sure how tiny you'll get it, but let's take the interesting one:
KRPPKRP.
That's having 3 pawns you know, that really reduces the EGTB.
The 7 men in diep format are 585.845.413.676.228 entries
when counting all 3-6 men and the 4 vs 3, so not 5 vs 2 nor 6 vs 1.
I'd say ignore 5 vs 2 initially. If you have KQ vs King + 4 pieces that happens to be a draw instead of a win for queen, then you're just having
bad luck....
Of course generating all those EGTBs to get to the goal is a lot. It's 965 EGTBs all together (and in number of files nearly 2x bigger, as this is unique EGTBs, not number of files of white and black to move).
KRPPKRP is 295,125,079,056 entries.
That times 2 of course.
So it's 59.0GB uncompressed (times 2).
KRPPKR is uncompressed 6,769,796,880 entries
Default compression (not supercompression) it's having
sizes 224MB and 90MB.
If we project that in a stupid manner to the interesting 7 man EGTB
That's factor 43 larger for the 7 man.
224MB * 43 = 9.7GB. and the other one a lot smaller.
That's not supercompression yet though. Yet that fits easily onto a SSD
together with a lot of its 7 men brothers. I'd be prepared to buy a SSD for THAT.
Using that in search will be a huge advantage.