AndrewGrant wrote: ↑Wed Sep 12, 2018 7:54 pm Also, seldepth=3. Max tree size is <= 256^3. Its not a ponder bug, its a hardware issue.
Andrew,
May I quote you from CCCC chat?
A handful of engines (5) are randomly locked out of thread access, causing their trivial depth 1 searches to take well over a second, when usually they are < 1 micro second.
The working theory is that the 5 engines impacted are ones which realloc threads on each search. I know for example that Stockfish only does that at startup, so its less likely to be hurt by OS related tasking.
And now you're insisting it's a hardware problem...Its an OS problem. Getting locked out of CPU time is the fault of the OS
This occurs because of the hyperthreading and pondering. Windows is known to lock up contexts heavily
Stockfish does a 1 time thread alloc / binding. This reduces the overhead of swapping contexts, so the issue occurs less.
You were well aware of the hardware platform and intended configuration as early as Aug. 8th...and responded that you were happy to participate. At that time you said you had no interest in supporting pondering in Ethereal...yet you implemented it a short time later in version 10.88, and agreed to have it used in CCCC.
Our moderator Greg had a inciteful perspective:
NJ_Greg: @AndrewGrantEthereal FWIW, I see both sides... Authors _could_ take steps to address it (to deal with crappy OS), but it _is_ also a level playing field. Some engines are (at least sort of) OK with it.
That all being said, I told you in chat I would discuss with the chess.com team to see what we could possibly do in this regard but can't promise anything.
We'd certainly also not be happy if Ethereal missed the cut because of the way it handles thread allocation.