Hello, all! I saw some of you comparing kN/s, in another thread, so I thought I'd weigh in on this. You cannot compare Rybka's kN/s to another engine's kN/s. It's really sort of like comparing apples to oranges. You CAN, however, compare a specific version of one engine to the SAME version of the SAME engine on another machine. Each engine has different search algorithms and look for the best move in different ways. Compare it to searching for a lost child. Let's let one group of people wearing blue shirts, say 100,000 of them, look for that lost child in every city in the USA at the same time. Now, let's let another group of people wearing red shirts, say 10,000 of them, look at the same time, but in the city where the child was lost and in the city where his grandparents live. Which group is going to find the child first? We don't know. One engine may spend time looking like mad at every possible move, even the lame ones; and another might instead look hard at only what it feels are the good moves. Which chess engine will find the best move first? We don't know. As I understand it, Rybka might only have xxx kN/s on a basic system, but it's looking at what it feels are only good moves. I'm not touting Rybka, I'm just telling you how I understand it to be. See this article:

http://rybkaforum.net/cgi-bin/rybkaforum/topic_show.pl?tid=5727

From what I understand, Rybka has patented its search alogrithms. It doesn't need to look everywhere for the little boy, just in the cities w/ the best odds.

What you say is true, Rybka displays a radically different statistic than say Houdini. I think most of us are already aware of this difference.

Still, sometimes it's fun to compare apples to other apples. (i.e. The node count for my machine running Engine X to your machine running Engine X)

Also, the amount of hash also affects the reported kN/s.  More hash will give lower numbers because there will be more hash hits from transpositions which are not counted.

Interesting, did not realise that bit.