On 23.11.20 18:01, Fons Adriaensen wrote: > On Mon, Nov 23, 2020 at 05:25:34PM +0100, Giso Grimm wrote: > >> without --sync jackd2 uses multiple cores whenever possible, at the cost >> of one extra buffer. With --sync jackd2 behaves single-threaded but has >> one buffer less delay (i.e., two buffers like in jackd1). Using --sync >> is thus mostly relevant when delay is the primary concern, and not >> performance. > > Are you sure about the single-threading being controlled by --sync ? > I've never seen this mentioned before. > > AFAIK, with --sync jackd2 writes the outputs to the driver when > all clients have run, same as jackd1. Without --sync it writes > the outputs of the previous cycle before any clients run, > resulting in one period more latency but a bit more resilience > agains xruns. > You are right, sorry for the confusion. I always thought that the delay optimization was at the cost of multi-threading, but this is not true. I just tested with parallel graphs with heavy load in each graph, and I get a total jack load which roughly corresponds to the CPU load of the thread with the highest load, which confirms that parallel processing is possible also with --sync. Actually the jack load does not seem to be affected. -- Giso _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx https://lists.linuxaudio.org/listinfo/linux-audio-user
