tangosraka.blogg.se

These values show the number of positions the engine analyzed, which means that Stockfish prioritizes broader position search and higher search speed over time-to-depth speedup. Of course, the same engine cannot weaken when given better core support, so what does happen here? If we put aside the depth number, we can see that the other values, nodes number (4526m) and nodes per second (4944k), actually increased about 4 times. Note that the engines were run separately.ĭespite analyzing a minute longer, Stockfish 11 working on 4 CPUs reaches the same depth as the SF working on a single CPU. However, here’s what happens when Stockfish 11 is run on 1 and 4 four CPUs on a local computer.

But with fewer CPUs working, the higher-core engine has a lower depth speed.įor example, Stockfish working on 50 CPUs will analyze around 50 times more positions and will still reach higher depth much faster than Stockfish working on 1 or 4 CPUs. Of course, when the difference between the numbers of CPUs used is too big, then the time-to-depth speedup of the higher-core SF will also be higher (although not as high as one may expect from a much faster engine). Lower time to depth for higher core Stockfishįirst and foremost, it is a fact that a higher-CPU-core Stockfish can take longer to reach the same depth than a lower one. And regardless of whether you're a GM or not, if you use chess engines for your analysis, you have a good reason to learn the meanings and values of the numbers your engines show. We've prepared illustrative examples and statistics below to show you why NPS is so crucial. This value is known as NPS - nodes per second, and it reflects the number of positions the engine analyzes in one second.

There's a far more significant value when it comes to measuring the analysis accuracy. The top grandmasters never rely on the depth alone, for they know that the speed at which an engine reaches a certain depth (known as time-to-depth) is not a reliable measurement for the accuracy of its analysis. Lower depth speedup, on the other hand, is often seen as a sign of a weaker engine. This is because higher depth is usually associated with higher accuracy of a suggested move or variation. It comes as no surprise that while choosing between two engines, most chess players will pick the one which reaches a higher depth in a given time. Hartman’s concern fully, but we are glad to have been given the incentive to explore this topic more thoroughly and share our findings with all chess lovers. It took some extensive research to understand and respond to Mr. This was taken as a problem on our part since it's widely believed that faster hardware (or cloud server) must get you faster to the same depth. So the problem was that our cloud Stockfish engine, which worked on a faster server, reached the same and sometimes even lower depth than the local one. For instance, Stockfish 15 using four CPUs on local computer analyses around 5m nodes (positions) per second, while Stockfish 15 working on Chessify’s 300,000 kN/s cloud server analyzes around 60 times more positions per second. For those new to the term, a cloud engine, in this case, cloud Stockfish, is the same Stockfish engine run on powerful cloud (internet) servers, which, unlike average local computers, can afford exceedingly high speed and multiple threading. John Hartman, the digital editor for, tweeted to us that his "old quad-core I7, using the latest dev Stockfish," has a better time-to-depth speedup than the 55,000,000-NPS Chessify cloud engine.