Rybka 2.32 on an Athlon 1.2 GHz could not be that high......

[pichy]

There's no way that this could be right, especially considering that Rybka 2.3.1 on a single Athlon 1.2 GHz is well over 2900 on the SSDF list, which is calibrated to the FIDE list. It is believed by some (mainly to be safe and conservative in estimating ratings) that the computer rating lists are inflated by a certain factor for ratings different from a certain rating. Based on various human vs. computer matches with various programs, it is reasonable to believe that the rating for which the SSDF list is correct for that particular hardware is somewhere between 2700 and 2800, and that ratings lower than this are too low, and ratings that are higher than this are too high. Anyway, being very, very conservative and assuming that the ratings higher than 2700 on the SSDF list are off by a factor of 2 from 2700, this would still put Rybka 2.3.1 at a rating of 2820 on a single Athlon 1.2 GHz, and on 2.2 GHz, this could become around 2860 (again, a conservative estimated increase), and on a dual, it would be 2890 (another conservative estimated increase). In reality, not being so conservative, the actual estimated rating that would equate to a FIDE elo would probably be at least 2950 or so.

[Sergei Markoff]

There is a problem with camparing program and human strength in general, because say +100 Elo points vs other engines may probably mean only +30 points vs humans. There are a sort of positions in which humans had a good chances, I think most of this positions are about long-time positional maneuvering. If the engine gives one more search ply it helps a little in this positions but in tactical ones it can help much more. But in tactical positions programms are already stronger than almost any human. So, speedup provides huge help in play vs other programms and helps a little vs humans. That's why (in general because of totally different approaches of human and machine player) human ratings can't be directly compared to engine's.

[Dr.Wael Deeb]

There is a problem with camparing program and human strength in general, because say +100 Elo points vs other engines may probably mean only +30 points vs humans. There are a sort of positions in which humans had a good chances, I think most of this positions are about long-time positional maneuvering. If the engine gives one more search ply it helps a little in this positions but in tactical ones it can help much more. But in tactical positions programms are already stronger than almost any human. So, speedup provides huge help in play vs other programms and helps a little vs humans. That's why (in general because of totally different approaches of human and machine player) human ratings can't be directly compared to engine's.

Beautifuly stated Sergei
Dr.D