Latency issues?

EricSteffensen · Latency issues?

I was wondering if any other live performers using a Mac have had any issues with latency during their shows.

My setup is pretty simple, I've got a 2.4 Ghz Macbook with 4GB of RAM. I use a Presonus Firebox breakout box connected. I mix my sound using Garageband and just have three inputs open, one for my mic and two for the guitars I use, and then I stream using Nicecast.

The only time I get latency is when I have Garageband, Nicecast and Second Life all open and I'm streaming. It usually happens 5 - 15 minutes into a show and then I can't stand to monitor myself in headphones anymore so I take them off. If possible I'd like to keep them on because I think it keeps me more conscious about how close I am to my mic lol

Are there any settings that you can use that may help decrease or eliminate latency?

Slim Warrior

Eric, the best thing is to turn off all the sound in SL so you do not hear yourself again a few seconds later. You can still see the chat and can always listen back to your show using the nicecast archive option.

I use GB and Nicecast too with usually 2 tracks open ( monitor on ), you wont need more than two tracks with monitor on, one for vox and one for direct line input for guitar, If you are just using acoustic guitar then you can get away with one track open really with some good mic positioning Smile

hope this helps

Slimmie

Gath Gothly

So sounds like you're doing monitoring via software and getting latency due to that - right?

Certainly doing things like turn off all SL sounds, voicechat, video, music will help - as will turning of particles and especially putting that graphics slider in preferences down to the least intensive.

I decided to use two machines. A lappie just for being on SL, and a desktop machine that has my mixer plugged in and doing the streaming.

That of course helps latency with monitoring a ton if it's an option for you. It also helps with latency and jitter with your stream itself.

I use Linux, and jackd - not "real time" monitoring per-say. There's a latency of a few milliseconds there, but not really detectable to the human ear. I simply could NOT run jackd with monitoring how I wanted on the same machine I run SL on. SL just takes up too much of the machine's resources. The latency sucked and I had a ton of crackling and popping when I tried.

One thing that might help... and excuse me here being a linux nerd going to talk about kernel-level stuff...
Anyway, you could try to nice/renice SL up and your mixer/garageband/nicecast down.
If you don't know what nice and renice means... it means to give a process (application) higher or lower processor priority.

I'm afraid I don't know the GUI on a Mac, but I know the kernel, being BSD-based. There's probably a way to do it through the gui - normally in a "task manager" type thing.

I normally do everything at the command line, so sorry I'm not much help. But if you are comfortable at the command line, after launching all your apps, look up their process IDs with the ps command (ps -ef), then renice them accordingly. If you give secondlife a positive "nice" value, it has less chance to take up the processor. And if you give nicecast/garageband negative processor priority, it will get more processor time. The command is "renice" and "man renice" will give you the manpage to read up on.

It's one of those things you have to be careful with though. There's a balance you have to find or renice'd processes can just make things worse. Like make SL totally unusable because it can't get enough processor time.

In the end... it's really just easier to run with two machines than fight with processor priority trying to find that balance that lets everything run as smoothly as possible.

The other big options is, of course, a mixer with good hardware monitoring. You won't hear your software effects (if any) in the monitor, of course. My little m-audio mixer can do it, but I want to hear my software effects - so I use jackd instead.

RayW

Hmmm ... I'm going off topic in order to thank Gath Laughing

I run two machines. I run SL on my older one. But, the new client caused me to crash twice in one gig the other week. So, I tried running everything on my faster machine. OK, it works fine, except that I can either work SL or monitor my stream .. but not both. Plus, the "stream machine" is off to the side and I had to jack my whole layout around just to watch it.

BUT, Gath .. I'm going to turn my old SL machine preferences down to nothing. Good idea. May not be pretty. But, it may not crash, either.

Sometimes I'm just a newb!

OK, back to the regular scheduled thread!

EvaMoon

I run all my inputs through a mixer and monitor before it ever goes into the computer. I'm on a mac too, and even without anything else running, just listening to the computer output has just enough latency to be irritating.

I put all my GB/backing tracks/etc on an iPod and run the iPod into a mixer channel too. I bought a minijack to XLR cable just for the purpose and it works fine. I use a regular floor monitor running out of "control room out" on the mixer.

EricSteffensen

So what I'm thinking is that for my machine, SL is too much of a resource hog even with the graphics set on the minimum and sounds turned off to completely eliminate latency inside of Garageband for me.

I'm not quite sure if there is a way in the MacOS to nice/renice an application. Before OS X I remember you could assign a memory threshold to each application which may (or may not) be the same concept but I if that option still exists I'm not sure how to get to it?

So that leaves me with the options of using an external mixer or a seperate computer to run SL. I suppose if I ever want to dual stream that the mixer option doesn't work too well?

Silas Scarborough

Old saying: If you're arguing about whether the relationship can be saved, it can't be saved.

Same applies to performance on the computer, doesn't matter what size all the way up to mainframes. When you hit the limits you may get 10%-15% by fine-tuning this or that but you won't get any more than that unless some total dork has been managing the machine.

I'm using a MacBook Pro 2.5 dual and I frequently had four or five channels live and active. SL ran on the same machine along with Nicecast. I got some spurious clicks and pops every so often and that most likely means it was pretty close to the limits of its performance. There's a newer model with a longer-life battery that looks like a pretty good value.

I'll leave it to someone else to speak for external mixers.

If you can get yourself into a situation in which you're running SL on one machine and GarageBand on another, you'll have the luxury ride. It's expensive to pull it off but it's as reliable as you'll ever get with SL.

Does it really have to be a laptop? You can get SO much more boost out of a desktop machine and for less money.

the Professor · 2 machines; mixer

I run SL on my MacBook Pro. Nothing else. I run two mics (vocal and electric guitar amp with mic in front) through a Wharfedale Pro R-1604. The mix goes out to an iMac (desktop) that has only Nicecast running for the stream. I use some of the effects in Nicecast to sweeten the sound a little on the way out. I have a headset on from the mixer, mostly so I can hear myself singing. I'm on wireless (both machines) with Comcast cable modem. It's fast (way faster than was my previous dsl setup) . . . but there is a still latency.
I try to run a good sound check inworld before the show so that I don't have to worry too much about the sound once I start. If the venue is slow (few peeps) I grab a quick listen ab out 10 minutes in to be sure I'm not over modulating.

Silas Scarborough

I've never had a problem with latency but my solution has been expensive: throw as much compute power at the problem as I could possibly muster. In years gone by, that was a lot. Now it's laughable but that's a different story.

My primary machine until it dies is an 8-way Mac Pro desktop machine with 8 GB of memory in it. All monitoring was done via headphones on the Firestudio Project audio interface which is effectively a mixer, albeit a fairly brainless one.

SL was running on a 4-way Mac that was relegated to SL when it could no longer serve as the primary.

It may be possible to solve the problem in some artful way that doesn't cost a lot of money but that's never been my experience regardless of the size of the computing platform and I've designed them all the way up to z9 and z10 networks.

Chordslinger Carstenz is a friend of mine who went from nobody in SL to multiple tunes on the 61 home page in a couple of months. He's running all Macs and he's running big ones.

I know this probably isn't good news to a lot of people but really didn't you know the answer already. Seems to me the question isn't so much whether there's a performance problem but rather how to raise the money to do something about it.

(If'n you think we're bragging about having any kind of stuff at the Ministry of the Internet, brother, you don't even know.)

EricSteffensen

You're probably right Silas, but really none of these other options (external mixer or a 2nd machine) will break the bank. I would probably go the 2nd machine for SL route and would be surprised if some of the low end PC laptops that are selling for $400 - $500 wouldn't run SL.

However, if it is just a matter of tweaking settings than I'm sure I can put that $500 to better use somewhere else. There is a setting in Nicecast called "CPU usage/quality" that I'm curious about. The way I see it, Nicecast has the ability to act as a shoutcast server that would allow for multiple connections, which I imagine requires more CPU power.

But since when I'm performing, there's only one connection to my machine because I'm sending my stream to a third party stream provider which is what is streamed into SL. I'm thinking that I might be able to dial down this setting in Nicecast even more without affecting the performance of my stream.

Silas Scarborough

I've got the CPU use level set to about 75% in Nicecast but that's just Silas mumbo jumbo about never turning things to ten.

I don't use any Nicecast effects at all. My logic is that the audio software (e.g. GarageBand or Logic) will almost certainly be able to apply effects better and more efficiently. I DO NOT KNOW THIS FOR SURE.

The smallest configuration I've run successfully has been using a MacBook Pro 2.5 dual and that's running everything including the five or so live channels. I doubt it could run effectively on a smaller machine and it's a bit wonky even on this one.

There's a lot of value for all kinds of reasons in putting SL on another box as that isolates it from the purity of your music creation system.

I'm not clear on why you care about multiple streams as the only time you'd need to do that would be if you're using a daisy-chain approach in something that was once called a meta-jam. That's when you have a stream coming in to your system from some other performer. You embellish the audio in some way and then send it back out again. (I don't like doing it but others do and you can find an extensive discussion elsewhere in the forum)

You want your outbound stream to be as fat as you can possibly make it. You can get by with 64K but go for 128K or above if your system can handle it. The consequence of having insufficient power or a lame service provider is that you'll get drop-outs on the other end as the stream buffers / re-buffers.

What I suggest is to find a friend and to crank it up on a test sim. Keep pushing the number up until it fails AS VERIFIED BY YOUR IN-WORLD FRIEND and then back it down to a more conservative value. This will not give you 100% protection as performance will vary from one sim to another but what you will get is a lot more confidence about the acceptable bandwidth range you can use.

They like to blow stuff up at Pranksters. Ask around over there for some test time.

RayW

My feeling is that whenever you run a software solution, you run the risk of latency becoming an issue .. unless you have one honkin' piece of hardare.

I love my external mixer. I monitor at the mixer and have near zero latency regardless of whether my machine has locked-up or whatever (yes, I have a PC and I'm posting to the MAC group.. sorry).

Of course, I also have an external vocal processor and external guitar processor and other external possiblilites, as well as a line out from my Recording PC to play backing tracks. So, my 10 inputs can become full in no time ... but none of that affects my PC or my (near zero) latency.

And it was under $200 ... could get one cheaper 2nd-hand, too. But, the otehr stuff was WAY over that Laughing

Silas Scarborough

Latency issues?

2 machines; mixer