Re: [LAD] Tascam US-16x08 0644:8047
On Tue, 30 Aug 2016, Greg wrote: I suspect the previous USB chipset was causing me more problems than typical, as I am now very much enjoying the OOTB experience. I did see updates to the driver as well (workarounds/adding delays) in the time that had elapsed. I am told that all motherboard chipsets are less than they could be. Intel or VIA usb chipsets generate more interrupts than NEC (or maybe SIS). The defining factor it seems is the USB 1.1 part of things. There are two of them intel/via use the UHCI driver which expects the MB CPU to do lots of the work. Other chips use the OHCI protocol which does as much work as possible in the chipset. This one uses a NEC chipset but is USB3 so I don't know what the control protion is: http://www.newegg.ca/Product/Product.aspx?Item=9SIAA0D4C34273_re=PCIe_USB_card-_-9SIAA0D4C34273-_-Product For something more expensive that has OHCI in the spec: http://www.newegg.ca/Product/Product.aspx?Item=N82E16815114048_re=PCIe_USB2_card-_-15-114-048-_-Product I do not know where things fall in the OHCI/UHCI with USB3 chipsets... but I think we can be pretty sure Intel/VIA go the cheap way. Thing is, even if USB3 doesn't use the O/UHCI part of things, almost all multichannel USB audio interfaces do. It might be worth while having a list of known good chipsets/PCIe USB cards. BTW, even with uhci drivers, I found it made a big difference to: a) make sure the irq that goes with that driver/usb port is not shared. b) rtirq lists that usb port separately from the rest (IE. usb3 usb, not just usb) c) nothing else is plugged into that port via a bridge/hub whatever. This meant for me (on my netbook) only using the USB port on the right side, not using the second USB port on the right side... adding a hub to the left side USB port for everything else (I was running from a USB hard drive at the time). I was able to run the (USB 1.1) audio device with jack at 64/2 with no xruns with this set up. (Atom single core at 1.6Ghz) Test duration being overnight so 6 to 8 hours. (cron turned off, ht off(well told Linux only one core), CPU gov performance (also tried userspace at 800MHz with success), setting rtirq RTIRQ_NAME_LIST="usb3 snd usb". For someone who has done some real world testing: http://crimeandtheforcesofevil.com/blog/2016/07/25/so-hey-usb-chipsets-totally-matter/ Point seems to be, that those going portable who rely on onboard USB... you may want to load linux onto a Mac which I am told will have good chipset, or expect to have higher latency. This is ok for recording, not for softsynth or effects. Otherwise add a new USB card. I do not know if the UHCI and OHCI drivers can run side by side or if the internal USB would have to be disabled. -- Len Ovens www.ovenwerks.net ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Tascam US-16x08 0644:8047
That's awesome! I went back to using windows 7 for a bit with my audio device, until eventually I became fed up with the driver problems (not to mention windows in general) and tried linux again, this time on a different machine... and it worked! I suspect the previous USB chipset was causing me more problems than typical, as I am now very much enjoying the OOTB experience. I did see updates to the driver as well (workarounds/adding delays) in the time that had elapsed. As far as 'nice features', I believe that they are mostly useless to me as on windows they are 'printed', eg, compressor/eq are applied not only to the monitored output, but also to the bitstream received by the computer. I very much prefer to be able to capture the raw data and adjust compression/eq after the fact. In my case with an i5 and Ardour, I am able to run those same fx and push data back out to the device with usable roundtrip latency. (I use my US16x08 for live sound during music practice/rehearsal). However, for certain situations (less processor power - imagine controlling this device with your tablet!, or an application that is even more sensitive to latency?) I could see this being immensely helpful. Not only that, if we crack open this egg, there's the possibility that we could improve or pave the way to improving the signal chain within the device itself! I'm happy to test if you'd like to take this off-list. Please document and share what you have found! -g On Tue, Aug 30, 2016 at 01:45:47AM -0700, OnkelDead wrote: Hi Greg, if your request is still relevant I think I may help. On my PC the common alsa driver worked OOTB. I did process what you've mentioned and analyzed USB communication of Tascam US-16x08 in a Windows 7 VM, but my intention was to get access to all this nice features (compressors, EQs) the device offers from my Ubuntu Studio 14.04. As also an USB noob, several smoking heads and 2 weeks later I was able to patch my snd-usb-audio kernel driver to support all mixer interfaces of that device. Interested? Greets Detlef -- View this message in context: http://linux-audio.4202.n7.nabble.com/Tascam-US-16x08-0644-8047-tp96678p101024.html Sent from the linux-audio-dev mailing list archive at Nabble.com. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev !DSPAM:57c55a0e316809058321121! ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Tascam US-16x08 0644:8047
OnkelDead wrote: > I was able to patch my snd-usb-audio kernel driver to support all > mixer interfaces of that device. Please don't keep that information a secret. Regards, Clemens ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Tascam US-16x08 0644:8047
Hi Greg, if your request is still relevant I think I may help. On my PC the common alsa driver worked OOTB. I did process what you've mentioned and analyzed USB communication of Tascam US-16x08 in a Windows 7 VM, but my intention was to get access to all this nice features (compressors, EQs) the device offers from my Ubuntu Studio 14.04. As also an USB noob, several smoking heads and 2 weeks later I was able to patch my snd-usb-audio kernel driver to support all mixer interfaces of that device. Interested? Greets Detlef -- View this message in context: http://linux-audio.4202.n7.nabble.com/Tascam-US-16x08-0644-8047-tp96678p101024.html Sent from the linux-audio-dev mailing list archive at Nabble.com. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
