[LAU] MIDI over firewire on Linux?

[Len Ovens]

On Sat, 19 Apr 2014, Jonathan E Brickman wrote:

> That helps a lot.  Had not heard that USB3 was broken for low-latency 
> audio, I'll have to remember that.  The reason I'm suddenly interested

I should clarify. There are no (that I know of) USB3 Audio Interfaces made 
at this time. The problem is with USB2 Audio Interfaces plugged into USB3 
ports. The work around is to remove the USB3 driver and just use the USB2 
driver. This is fine for audio use, but means if you wish to use the USB3 
port for a USB hard drive on the same machine, it will be slow (usb2 
speeds). I do not know if this affects the USB2 ports on a machine with 
USB3 hw, but one of the musts with USB audio is finding a USB port with a 
clear IRQ... which might happen to be one of the usb3 ports. Also there 
are some machines (mostly laptops) that have only USB3 ports available. 
There are apparently some scanners that have problems too. Intel has 
called this a "non-problem" saying the software should just have the unit 
"resend" any bad packets... not low latency words.

If USB3.1 has a new plug format, it will be usb3 only and this may force 
the audio interface producers to design a USB3 audio interface that may 
not have these problems. They have not done so at this time because there is 
no need to, the USB3 spec does not add anything for the audio world. A 
laptop with no usb1/2 ports might change that. An audio IF that plugged 
into a USB2 hub plugged into a USB3 port is probably not a good low 
latency audio solution.

I had not heard of the insertion count thing before. That is good to know. 
For a lot of people it will not matter as they only plug things in once 
and leave them. But for mobile use it sound like spending the extra for 
reliablility is worth while. I wonder what the numbers are for the 
standard "D" conectors are (like serial or VGA).

--
Len Ovens
www.ovenwerks.net