Topic: The answer to latency pops and clicks, improve latencies M.S.I.
I had, as all of us have, problems stabilizing my new audio workstation. Instilling fresh windows 10. Installed RME drivers for my UCX, both USB and FireWire to see if anyone gives better results.
First try not impressed at all :-(
So I go thru all the old tweaks to see if something helps. Nadia, I get depressed. Time to do hard internet search.
Looking at the resource list of irq sharing on this computer reveals the problem at once: The graphic card is sharing irq with both USB and FireWire controllers all on irq 16! Reading on internet, irq sharing is supposed to be "OK" and something that drivers are supposed to completely support, right...
I started looking at the irq numbers, and being not young anymore, I see something new to me, negative numbered irqs, what is this? Answer: Message Signaled-Based Interrupts = MSI.
This is a more modern approach to interrupts that goes beyond irq sharing. Can all devices do this? No, but some can and this can have a HUGE HUGE impact on your system. In the link below I will share a document/link that describes the process of changing the way devices use old irq or the new MSI.
USB version 2 can not use MSI but 3 can.
First of NVIDIA support this and switching to MSI made irq sharing with the USB and FireWire controllers go away. This was the moment of eureka. Reboot and test, BINGO! Rock stable both USB and FireWire, not pops or clicks. Started Firefox with lots of tabs while playing guitar through the DAW just to be nasty to the system, still no pops or clicks. Started Latency Monitor because it can produce pops and clicks sometimes, same result, perfect audio!
So I tried to put the FireWire controller in MSI mode and it started up, but the UCX was not detected by the RME drivers, I wonder if this can be fixed, because it seamed that the FireWire card was detected without any errors by windows.
This is the cure to our problems with irq sharing, that still exist today. You can do this with lots of devices, do be careful with your system while tweaking.
Here is the resolution: