I have the same problem. Upgraded from 2.2 to 2.4 yesterday. Also excganged the legacy KNX binding for the 2.x version and redid al my config (hours of work!). The KNX things file is about 280 lines, with about 40 things and 150-200 channels.
The performance is terrible. Indeed over 30 seconds before a command from the UI (classic or habpanel doesn’t matter) reaches the KNX bus. Often there is even no response at all. Sometimes there’s a quicker response but on average it’s dozens of seconds.
The problem is not on the KNX bus, there’s no flood of telegrams or anything. I think it’s really just a performance problem. I’m running OH on an RPI and when running ‘top’ I see the load average going over 2-3 when running ‘idle’ (that is: no abnormal activity going on). The java process is always the top cpu user. After disabling the v2.x binding and reverting to the legacy binding (yay for source control), the performance is back at crisp speed. I can see that the java process cpu usage dropped to about 1-10%.
Btw, I tried resetting the cache, this didn’t solve anything.
I assume there is loads of overhead introduced with the things and channels compared to just the bare items and that this causes performance problems on lesser hardware. Is this issue going to be addressed? Or are we supposed to resort to heavier hardware (meaning more power usage)? For the time being I’m sticking with the 1.x binding and I hope it will keep being supported until the problems are addressed.
