I would like ask is ROS optimized for CPU multi threading ?
As I am considering swapping for my AP’s + PTP’s - 912UAG-5HPnD, 911G-5HPnD, 911G-5HPacD boards for RBM11G + R11e-5HacD?
Or can someone recommend a better ROS upgrade option ?
ROS as a whole is multi-threading optimized as much as underlying kernel is … kernels 2.x were not that great, hence ROS 6 exhibits a few multi-thread un-friendlinesses (such as interrupt handling by CPU0). Later kernels are better in that regard, so ROS 7 should be better.
Then there are services/functions which can hardly be effectively multi-threaded (I’m not an expert, but gossip goes that BGP route updates are best left single-threaded).
And there are reasons to have single connection handled by single thread (e.g. single TCP or UDP connection is handled by single CPU core), such as making sure packet order doesn’t get affected by diffeence in processing speed when processed by different cores … connections generally don’t like out-of-order delivery, in best case there’s only a minor performance hit due to additional processing by receiver (includes higher memory consumption) and worst case is connection drop, with mid-case where there are many retransmissions affecting throughput more than sequential processing in RB.
But when running multiple parallel connection over a multi-core ROS device one should see pretty even load over all CPU cores …