LATENCY!

nodonnel · Post by **nodonnel** » Tue Feb 05, 2008 9:35 pm

Hi, I am an electronic performer who pipes all of his audio through live. I run an up-to-date installation of Live 5 (sounds like an oxymoron, I know) on an iBook G4 1.2 Ghz w. 768 megs of RAM; I have a Lexicon Omega USB audio interface.

I'm posting here because, although I use an assortment of moderately clever tricks to get my rig to work, I would greatly appreciate any advice to get my latency down. As reported in Live's "Preferences" tab, I have a latency of 27ms (13.5 in and 13.5 out) when I set samples to 512 , whether I use built-in audio or the Lexicon.

I would greatly, supremely, enormously appreciate any input on how to correct this problem. I don't think I should be getting 27ms latency at 512 samples. Please help! Thanks,

Nate

ctx · Post by **ctx** » Tue Feb 05, 2008 9:42 pm

USB/firewire inherently has some extra latency in it. You may be able to tweak it a little lower, but USB/firewire latency will never be as low as a properly set up pci, cardbus, or expresscard interface. If latency is of critical importance you should choose one of the latter; should be cardbus/pcmcia on your laptop.

Tone Deft · Post by **Tone Deft** » Tue Feb 05, 2008 9:45 pm

ctx wrote:USB/firewire inherently has some extra latency in it. You may be able to tweak it a little lower, but USB/firewire latency will never be as low as a properly set up pci, cardbus, or expresscard interface. If latency is of critical importance you should choose one of the latter; should be cardbus/pcmcia on your laptop.

I disagree, I can get down to 4mS latency with a USB card. what are you basing your info on?

higher sample rates mean lower latency but more CPU load and larger files.

it's also a good idea to keep up on the latest drivers.

grizzler · Post by **grizzler** » Tue Feb 05, 2008 9:50 pm

I didnt find any audio drivers for my mac just the core audio ones...

doc holiday · Post by **doc holiday** » Tue Feb 05, 2008 9:59 pm

nodonnel wrote:Hi, I am an electronic performer who pipes all of his audio through live. I run an up-to-date installation of Live 5 (sounds like an oxymoron, I know) on an iBook G4 1.2 Ghz w. 768 megs of RAM; I have a Lexicon Omega USB audio interface.

I'm posting here because, although I use an assortment of moderately clever tricks to get my rig to work, I would greatly appreciate any advice to get my latency down. As reported in Live's "Preferences" tab, I have a latency of 27ms (13.5 in and 13.5 out) when I set samples to 512 , whether I use built-in audio or the Lexicon.

I would greatly, supremely, enormously appreciate any input on how to correct this problem. I don't think I should be getting 27ms latency at 512 samples. Please help! Thanks,

Nate

You need to set samples lower, but with that G4 you will probably get dropouts if you go down to 128.

Timur · Post by **Timur** » Tue Feb 05, 2008 10:08 pm

If you are using VST plugins then check wether Live 5 already offers the "Plugin Buffer" preference setting. In Live 6/7 it is set to equal the audio buffers setting by default (in 6.10 it doesn't work anyway). If Live 5 offers this setting then change it to a set value of 512 and try to lower your audio buffers. If this doesn't work then leave your audio buffers at 512 but try to lower the plugin buffers to something like 256 or 128 samples (anything below 256 will increase CPU load though).

Also have a look at your USB audio drivers. Besides audio buffers they may also offer a setting called USB buffer, try to set it as low as possible (could work as low as 1 ms).

doc holiday · Post by **doc holiday** » Tue Feb 05, 2008 11:31 pm

Timur wrote:
Also have a look at your USB audio drivers. Besides audio buffers they may also offer a setting called USB buffer, try to set it as low as possible (could work as low as 1 ms).

a lot of audio devices use the core audio driver in OS X, so there are no drivers

leedsquietman · Post by **leedsquietman** » Tue Feb 05, 2008 11:58 pm

It should be possible to get lower latency, but the specs are somewhat dated on that older Powerbook, so trying to run it at less than 256 samples (around 12-15 ms) might be too much for the CPU unless it's a very simple arrangement with audio tracks that don't use many *or any* fx plugins and no virtual synths (or frozen/flattened).

Check to see if there is a new driver. I downloaded a new driver for my Alesis IO14 firewire interface recently and it's performance at 256 and 512 samples was 4.1 and 4.8 ms respectively better than the previous driver, a heck of an improvement, Do you have to use the core audio driver? I thought mac users had the choice to do either or *core audio or ASIO *

nodonnel · Post by **nodonnel** » Wed Feb 06, 2008 12:22 am

Unfortunately, I don't have a choice of which driver to use--it's coreaudio only for me. I'm currently messing around with different sample #s, and I'm getting results that are at least acceptable. I have to say that the coreaudio driver being in a black box does not seem to be the best solution to me, but I could be wrong.

I'll keep messing around and post my results, lest they help another soul on the quest for negligible audio latency on a budget--Thanks for helping out!

Timur · Post by **Timur** » Wed Feb 06, 2008 11:24 am

doc holiday wrote:
Timur wrote:
Also have a look at your USB audio drivers. Besides audio buffers they may also offer a setting called USB buffer, try to set it as low as possible (could work as low as 1 ms).
a lot of audio devices use the core audio driver in OS X, so there are no drivers

I speculated that Core Audio would allow to set USB buffer size as well. Anyway, I compared Nodonnel's 13.5 ms to my PCI card at 512 samples, which comes up at 12.3 ms. So obviously the USB buffers are already set to 1 ms anyway.

So if pushing the hardware is no option then the only alternative I can thing of is looking for that Plugin Buffer setting in Live's preferences. For explanation, the default setting of setting Plugin buffers equal to audio buffers means that whenever you lower audio buffers to 256 samples, plugin buffers are lowered as well, for a total of 512 samples latency. At 512 sample your total is 1024 samples, so if you can set those plugin buffers to 512 samples and change audio buffers to 256 samples you get a total of 768 samples, which is at least half a step into the right direction when working with external VSTs.

LATENCY!

LATENCY!

Re: LATENCY!