On Sat, 2012-12-22 at 18:37 +0800, Ho Wan Chan wrote: > Also, can you provide us a comparesent on the performance and audio > recording on both the 3.5-lowlatency and the 3.6-rt kernel:-P
My audio card does not work properly. It doesn't matter what kernel is booted, I always get xruns. Latency is bad with both kernels. Linux can use 2 of 8 ADAT channels only. RME is willing to help, but I don't have the abilities to write a driver and nobody from ALSA did reply. At the moment I don't have a Linux production environment and I don't see that this will change in the near future, so I'll test FreeBSD as soon as possible. The developer of the FreeBSD driver is interested in testers, I don't had to write him, he did wrote me. Unfortunately FreeBSD isn't a real-time OS. However, I can't give any valid information about kernel performance. Before I bought my card, I did a lot of research and asked the community. Shit happens, the information was wrong. I only can inform everybody that the RME HDSPe AIO does not work for Linux and all the time people claim that all RME PCIe cards should be supported by Linux, I only can correct them, to avoid that other users spend that much money for a card that isn't supported by Linux. For sure, even for this RME cards there are differences regarding to the Linux distro and/or kernel I use. So one big difference between kernels is, that later kernels handle the graphics IRQ. I can't reboot right now, but IIRC Quantal's lowlatency kernel already does ensure that the graphics gets it's own IRQ too. The 3.6-rt kernel at all events does ensure it. So, for hobby usage there isn't really a difference (did not test with external MIDI equipment, there might be a difference) between the both kernels. With both kernels, professional usage is completely impossible. I tweaked my Ubuntu completely. $ cat tuning #!/bin/bash # sudo bash tuning - Ubuntu Studio Quantal # 2012/Nov/04 ### http://www.mythtv.org/wiki/PCI_Latency ### http://wiki.linuxmusicians.com/doku.php?id=system_configuration#pci_bus_latency ### Bluetooth service bluetooth stop ### Network #service network-manager stop #service networking stop # does cause serious issues #modprobe -r r8169 # Ethernet NIC driver ### TerraTec EWX 24/96 modprobe -r snd_ice1712 ### Others modprobe -r firewire-ohci modprobe -r firewire_core service cups stop modprobe -r ppdev # parallel port modprobe -r lp # printer ### Unbinding devices echo -n "0000:00:13.2" > /sys/bus/pci/drivers/ohci_hcd/unbind echo -n "0000:00:13.4" > /sys/bus/pci/drivers/ohci_hcd/unbind ### Log file l="log/tuning.log" #echo "$ lspci -v " > $l #lspci -v >> $l #echo >> $l echo "$ /etc/init.d/rtirq status " > $l /etc/init.d/rtirq status >> $l echo "$ grep 18: /proc/interrupts" >> $l grep 18: /proc/interrupts >> $l echo >> $l echo -n $(date)" - "$(uname -r)" - " >> $l cat /etc/issue >> $l echo "##############################" ; cat $l exit 0 Other things, e.g. frequency scaling and enabling hr timer is done by the scripts, to start my audio sessions. I can stop network-manager too, but this will not change anything, disabling networking does cause issues. Usually I would not disable the TerraTec EWX 24/96 cards, because I still like to use them as MIDI interfaces. Regards, Ralf -- Ubuntu-Studio-users mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-studio-users
