The default kernel in Ubuntustudio is indeed 'low latency'. What you want though to get the best performances is a 'real time' kernel. 64studio comes out of the box with a 'real time' kernel. Ubuntustudio doesn't come with a 'real time kernel' by default, but you can install it ( cf sticky on the 'multimedia production' section of the ubuntu forum).

If you want a solid and efficient audio environnement on linux, my feeling is that you probably found the right place with 64Studio.

I can't help you much for your higher latency on 64Studio than WinXP. You should at least get the same results on both systems. Hope someone here can help you to sort this out.

You will probably need to give a bit more infos about your system to get serious help...

Good luck!

Yes, I suspect you might have your settings muddled...

On my system, the best latency I could get on XP was around 5ms for my Hammerfall. Which was not so good considering that the moment I started doing any kind of post processing on it, the latency easily climbed to 20ms or more. 64Studio can give me 2.5ms without Xruns for the same hardware and under full effects load. Definitely real time kernel.

Wish I had some help regarding those settings for your hardware... Have you tried periods 3?

Cheers

Thanks for the help. That solves at least one of my questions.

In response to the periods 3 query, No I have not yet tried it. I had read somewhere that the optimal setting was 2, but I suppose it all depends on my hardware.

Hardware:
Computer:
Averatec 2300
Amd Turion 64 X2 TL-50 (1.6GHz)
1 gig DDR2
100 gig SATA HDD
Dual Layer DVD+/-RW
nVIDIA GeForce Go 6100
1 Firewire (4 pin)
3 UBS 2.0
4-in-1 Media Reader
12.1" WXVGA Display
Sound Card:
M-Audio Duo

Maybe Jack is not seeing your M-audio card but your on-board audio card. Type in the terminal: "cat /proc/asound/cards". If you see
0: Intel-Hda (or something similar, your on-board audio device)
1: Your-M-Audio-card
then you should choose hw:1 as your interface in the set up.

BUT, if you don't need to use your on board audio device at all you'd better disable it in the BIOS, as I did following the hint by Quentin in the funny thread "newbie has silent audio disk". Then cat /proc/asound/cards should output "0: Your-M-Audio-card" and you can choose hw:0 or just "default" as your interface in the set up. If you have got more than one card you intend to use, then follow user's FAQ #13.
I've got Frames/Period: 64 Sample Rate: 48000 Periods: 2 for my M-Audio 1010LT. That results in a latency of 2,67 msec with very few xruns. So yes, it must be.

Cheers
Pablo

I made sure Jack was recognizing the Duo. I was not aware of that command you suggested, but I opened up the device menu and selected hw1, which was my Duo.

Last night I played around with the settings a bit. I turned on shaped dithering and it seemed to help a bit with the xruns. Currently I'm at 48000sample, 1024frames, 2periods. It seems pretty stable, but every now and again I get an xrun or two.

Are xruns a normal thing or should I not experience them with the right settings?

Also, what do the numbers in the xrun counter stand for? [a(b)] Is "a" the input xrun count and "(b)" the output xrun count? Or are the numbers codes?

Hardware:
Computer:
Averatec 2300
Amd Turion 64 X2 TL-50 (1.6GHz)
1 gig DDR2
100 gig SATA HDD
Dual Layer DVD+/-RW
nVIDIA GeForce Go 6100
1 Firewire (4 pin)
3 UBS 2.0
4-in-1 Media Reader
12.1" WXVGA Display
Sound Card:
M-Audio Duo

Hi saghaulor,

If your Duo is USB then you should definitely be using 3 periods, not 2. It's to do with the internal hardware architecture of USB audio devices - the usual default of 2 periods relates to PCI cards. After changing that value you should be able to go down to 512 or 256 frames without trouble.

Also, if you aren't using the external inputs on the Duo you can run Jack in playback rather than duplex mode, which improves performance a lot.

As for the two separate numbers in the xrun count, they represent two different checks for buffer under-runs. Ideally, you should have a zero both inside and outside the brackets. Depending on how important very low latency is to you, you may wish to risk an xrun on application open or close. This can cause an xrun if you're riding on the edge of what your interface and computer can achieve.

Cheers!

Thanks for the input on the 2 vs 3 periods applying to my audio card. I'll try it out. I know when I messed with it once, the latency skyrocketed. Oh well. I guess latency isn't that big of an issue for what I'm doing, but it would certainly be nice to have it performing the way it did in WinXP.

On a side note, I thought the moderator had deleted my thread, then I realized it had be bumped up the ladder. Cool beans.

Anyways, thanks for all of the help ladies and gentlemen.

I opened up jack, and switched the periods to 3, as was previously suggested by Daniel. Then I began tweaking the frames, trying to get lowest possible latency with few or zero xruns.

The 3 periods seemed to only destabilize jack, causing more xruns than 2 periods, this is even at 2048 frames, and 48000 sample rate.

So I went back to 2 periods. I then began to play around with the frames. I have it currently set to 48000 sample rate, 2 periods, and 2048 frames, this seems to not incite any xruns. The latency is under 40ms if I am not mistaken. Nonetheless, the buffer is marginally noticeable, if noticeable at all.

I can run jack at 1024 frames and only incur buffer underruns every so often. But I tested it while recording and the xruns were heard in the recording. This is not acceptable so I had to move the frames back up.

Interestingly enough, Ardour reports a lower latency than Jack. So there is not too big of a problem.

Now, I have a new problem. Last night after I tweaked Jack enough to get it stable and running fairly fast, I thought I would give jackmin a go. As soon as jackmin loaded xruns began to skyrocket through the roof. I'm not sure why this is happening. Any ideas?

Correction:

Ubuntu Studio DOES come out of the box with a real time kernel. My Grub bootup verifies that by saying "RT" for the kernel selection.

Now vanilla or General Ubuntu doesn't come with the RT kernel. However, you can load on the RT kernel without the need to upgrade fully to Ubuntu Studio. However, by doing that:

1) You don't know if you could be missing out on good applications
2) Everything in Ubuntu Studio is already set up to use Jack.

So some configuration work is done for you.

However, I guess the reason why we are here at 64studio is because we were looking for something better than Ubuntu Studio. Unfortunately US has problems right now. I want to get to using audio straight away. So pretty much for me I am looking to evaluate my options with other distributions and I narrowed that choice down to either JackLab or 64 Studio.

JackLab does have quite a few pros going for it...but a HUGE pro for 64Studio is that it is Debian based. ...So is Ubuntu. So shorter learning curve.

Anyway. Just to let you know that Ubuntu Studio DOES come with the RT kernel, but standard (or General) Ubuntu doesn't.

Geo

..gives me woes too. But mine are quite different (overheating). The performance however is perfectly well. Around 8ms latency stable with ardour plus zynadd plus others running normal.

I also recommend to try it with JAD - it has some differences to 64Studio but is still a Linux tuned for musicians.