30 Nov
2017
30 Nov
'17
7:30 p.m.
"Jeanette C." <julien-3g/GUrBLTNIb1SvskN2V4Q(a)public.gmane.org> writes:
Nov 30 2017, Peter has written:
Dear Peter,
...
Well, the problem is not as much your cards but the disk I/O. Getting
more buffers will already help (-n 3 instead of the default -n 2). You
can try improving this problem by using rtirq to distribute realtime
priorities: do you already use threaded irqs?
--
David Kastrup
this looks indeed pretty slow, is it an external
usb-2 drive?
No, it's an internal S-Ata drive, apparently a SAMSUNG HD154UI.
You may perform a simple check:
sudo hdparm -tT /dev/sda
For cached reads this averages around 1200 MB/Sec, for
buffered reads
around 108 MB/Sec. I didn't find an option to test the writing speed. As
a write test, I tried this:
dd if=/dev/zero of=out.file bs=1M count=100
with a result of around 560MB/Sec
If your are just recording, can you increase the
buffer length in jack?
I could, but I already have it a period size of 256. At 512
I started to
get a noticeable delay. With cards that can potentially go down to 64
samples, I feel a - perhaps unreasonable - hesitation to set the period
higher. Is this very unreasonable?