Stockfish on IPad 2 what is it rated?

[JAMerolle]

I looked on many list but have not seen it, any help would be great. I posted before but knowone has answered me.

[royb]

I hope you do get an answer. I asked previously and got nothing on this. My guess is 2700 using the scale that CEGT uses but that's just my guess; I have no data to back that up.

[styx]

how should someone know? for an accurate rating, stockfish on the ipad must participate in a human tournament. if you say "ok I only want to know it's rating compared to the CCRL or IPON engines" you could compare the speed of your ipad-sf with the speed of a desktop computer-sf used in these rating lists. if the desktop-pc is, let's say 20x faster, then maybe someone can guess the resulting elo difference.

[royb]

My MacBook Pro processor (2.3 GHz i7) runs only 3.57 times faster than an iPad 2 (comparing stockfish 2.2.2 speeds on both CPUs).

3.57x faster implies roughly 60 Elo strength (I see 35 Elo per doubling these days, not the 50 or so that used to seem the norm about 4-5 years ago). If that holds, then Stockfish 2.2.2 on CEGT is rated roughly 2973, so perhaps 2900 (on the CEGT scale) would seem the right neighborhood for the iPad 2 version of Stockfish.

Even if we allow for some pessimism, perhaps 2800? Pretty darn strong actually.

[royb]

I cannot edit my post now but I must have mis-typed on my calculator. My Mac 2.3 GHz i7 CPU is 4.6 times faster than the iPad 2, so that means perhaps 80 Elo difference between the Mac and the iPad 2 for Stockfish. Even so, that doesn't drastically change the numbers.
Perhaps 2800 is a realistic conservative strength estimate (again, using the CEGT rating scale).

[ernest]

I see 35 Elo per doubling these days, not the 50 or so that used to seem the norm about 4-5 years ago).

That's a pretty extreme view!
60 to 70 Elo per doubling still seems the mainstream observation...

[royb]

Really? I do not agree. My recent casual perusal of the CEGT rating list seems to suggest much less ELO gain these days for going from 1 to 2 to 4 CPUs. If I remember right, Houdini and Critter and Stockfish gain much less than 60 or 70 ELO when going from 1 to 2 CPUs and then again to 4 CPUs.

[ernest]

going from 1 to 2 to 4 CPUs.

We were speaking about doubling speed, not doubling CPUs...

[royb]

Oh yes, you are correct. I was saying one thing (typing one thing actually) and thinking another. Roughly 35 ELO per doubling of CPUs is what I was referring to. My apologies.

[JAMerolle]

Thanks for the help , of course I was only talking about computer computer matches. I know the SSDF has a nice spectrum of platforms so I thought it might be there but its not.