Interesting 6 man Sygyzy effect with high end hardware

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.
Post Reply
Dann Corbit
Posts: 10468
Joined: Wed Mar 08, 2006 7:57 pm
Location: Redmond, WA USA
Contact:

Interesting 6 man Sygyzy effect with high end hardware

Post by Dann Corbit » Mon Mar 16, 2020 8:01 am

In the past, I have noticed that Syzygy tablebase files did not need to be on a fast disk.
With my 3970x, that is no longer the case.

I have been analyzing some positions at long time control, and I noticed my NPS going from 80M NPS down to 13M NPS. So I looked at the performance monitor and saw my 1TB thumb drive was read saturated at 100%. It is a couple years old, and not stupendously fast. I was getting a few million bytes per second read rate. So I moved the Syzygy files onto a super fast gumstick SSD made for PCIE 4.0, and the NPS shot right back up to 80 million and the I/O saturation below 20% for the m.2 gumstick drive.

My theory about this is as follows:
For sparse positions that only need a few tables, they quickly get cached and you get pretty close to memory speed. But for complex positions that may need dozens of TB files or more, a really fast drive is important.

At any rate, it was a revelation to me.
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.

Post Reply