LostTactic wrote on 07/14/12 at 21:40:03:
this is probably a stupid question, but if someone is willing to answer would be appreciated. in the analysis panel (when you have an engine running) where it says "4 cpu" what does this mean? I've noticed this can be increased and decreased as well and this seems to reduce the kN/s amount, I'm guessing when the kN/s is higher it is analysing more per second? also is there an optimal cpu level to set it to?
It seems you have a computer with 4 CPUs. Your Rybka Aquarium discovered these CPUs on your computer and ran them by default. CPU means "central processing unit" It is well explained here:
http://en.wikipedia.org/wiki/Central_processing_unit So when you run an analysis all your 4 CPUs are calculating. Which means you have your machine at full speed. If you, when running an analysis, change this to 3 CPUs for example, the k/n's amount is reduced, too. The 4th CPU is not calculating and it is waiting for you to give it another task.
...And that's the best thing you can squeeze out of your Aquarium software. Imagine this: Put a position for analysis - run Houdini 1.5a on a single CPU (1CPU), then run Rybka 4.1 on another CPU (1CPU). And the next one can be Critter 1.6a working on the 3rd CPU. And all this while you use your last (the 4th one) CPU to browse the Internet, to work with other non chess related software...or whatever.. After a while you'll have three different opinions about the above mentioned position - Houdini's, Rybka's and Critter's. Three different analysis done at the same time!
What is more, you can use all this in a similar way for three positions.. You put a position, run Houdini on 1 CPU, then put another position and run Rybka 4 on the second CPU in the same time. The third position can be analyzed by Critter using the 3rd CPU. ...And still you can reserve your 4th CPU for other tasks. Of course, you can use your 4th CPU for another position/engine, but wouldn't it be too much for your poor PC?!