Hey, guys, I found the way to use 2 ASIO devices with REW, check this out
Thanks! And great measures!
Just tried and it's actually working with only one instance of REW, and the two ASIO devices
Now, I checked something : if I disable the WDM driver of one device (you can do it in Windows device manager, ant it doesn't disable the ASIO driver of the same device), the device does not appear anymore in ASIO4ALL, so ASIO4ALL act itself as a ASIO driver that you can select in a software, but it's not using ASIO driver of all audio device, if any at all. Once I unabled the WDM driver again, the device was back in ASIO4ALL
Did you try it ? (disabling the WDM driver to see if ASIO4ALL still see your devices once relaunched)
If it uses WDM drivers, you can still be limited at 16bit on some devices, which is not the case with ASIO, but at least you can use both devices at the same time
The ASIO driver uses a single callback at soundcard period boundary for passing samples in both directions - see method bufferSwitch at
https://github.com/mhroth/jasiohost#example . If the two soundcards are clocked independently, the single call will eventually get out of sync with the slave soundcard, causing sample drops in the slave direction.
Need to check it more, or wait for what
@IVX got, but it would appear that ASIO4ALL doesn't communicate with the devices with ASIO, it uses WDM only. The only ASIO link would be between ASIO4ALL and the software.
Yet, each device certainly keep is own clock, and I will try to test it without sync, and with (I can via SPDIF, ADAT and Wordclock)