[Ardour-Users] Enough Already was Sync between internal and external sources

[Geoff Beasley]

On Friday 23 January 2009 08:06:31 Mark Greenwood wrote:
>  It referred to latency in the hardware
> itself. I'm using a Firewire Edirol FA-66. Might there be some extra

for a serious comment tho Mark, all computer systems induce some latency 
somewhere; it's just not even theoretically possible to get no latency at all. 
the real issue is what i would call "unmusical slip" which i have never 
experienced in all the years i've used linux. in other words random 
'expansion/compression' of real time due to system overheads and priorities. 
Windows in other words. You set the amount of latency your system and hardware 
can cope within Linux and that's what you'll get...consistently.

even crappy hw can get very stable low latency; fact.the lower the system 
latency, the lower the actually recorded/monitored latency. now, the question 
is what to look for. obviously your kernel config is simply the most essential 
part to get right.how about you paste your kernel config  file on 
www.rafb.net/paste/ and we'll look at it.

 what distro/kernel/alsa/?  run hdparm on your recording drive and check for 
throughput.have you tried running as root as an experiment?  try recording 
ardours' click into a track  (through your sound card), create a new track and 
repeat  multiple times and compare the results whilst tinkering. using the 
secondary delta clock set to ms, put your PH on the beginning of one click and 
moving the mouse will measure the distance to the next click. you can check 
the gap between them quite accurately. that's your 'round trip' latency 
ARDOUR>HW>HW>ARDOUR. that's what ardour shows in the title bar.

 
hth

g. 



-- 
Geoff Beasley.
Composer,Performer,Producer.
Laughing Boy Records
www.laughingboyrecords.com
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