Multiple Instances of Guitarix Causing Xruns

[i2productions]

Gotta say, guitarix has come a long way since it started! I've been using it A LOT lately! I was still using lots of amplitube 2&3 VST(via festige) for guitar work. After giving guitarix a more thorough test I started using 2 instances of guitarix in a few resent projects. My Xruns were building up, and it took me a while to figure it out. In the 2 projects I was working on, closing the second instance solved the xrun problem. I was getting 10-20 Xruns a minute with 2 instances. Left a project open for 12 hours and came back to 58k Xruns! In both cases I was using Ardour 3(beta 4 when I first noticed the problem, and beta 5 now that I figured it out) and Reason 5.0 via wineasio.

[autostatic]

Weird, I can use multiple guitarix instances without any issues. Did you check the DSP load? Shouldn't be an issue unless you're using LADSPA plugins within guitarix. I just found out that the C* tonestack LADSPA plug-in makes DSP load jump to about 80%.

[i2productions]

I'm starting to narrow down the issue. It seems to actually be specific amp head sims. A few of the feedback ones (like 12AT feedback.) But then I can't reproduce them with frequency. It may not be the second instance as much as specific rack modules. I'll get back to you when I narrow it down more.

[brummer]

I'm starting to narrow down the issue. It seems to actually be specific amp head sims. A few of the feedback ones (like 12AT feedback.) But then I can't reproduce them with frequency. It may not be the second instance as much as specific rack modules.

This is very unlikely. From the inside view of a guitarix instance, it is completely insignificant how many instances are run.

There is just one unit witch could lead to Xrun's , that's the Convolver(s), when you use real large IR-files with it. But the limit therefor is given by your hardware.

Closing a second instance to avoid Xruns, isn't a indicator that the Xruns be produced by guitarix, but more a indicator that your system is driven near the limit.

[i2productions]

As far as system resources, I've got an I7 2.93Ghz processor, and when I've seen these xruns my dsp load is less than 50%. But as far as I've seen, certain amp heads seem to be the cause but I'm still not 100% sure. I've been lead to believe this as if I set the amp head sim to ---------- the xruns stop. So as I stated in my previous response I don't think it is the second instance, but I do think there is more wrong than just the convolver. I'm still trying to figure out with certainty what the problem is, so calm down and let me make sure I can reproduce the problem in different projects. Because I'm only running into it in 2 of my projects even though I use similar settings in others.

[brummer]

Just for clarification, there is nothing wrong with the convolver, it is just the way it is, to large IR files leading to Xruns, how large the files could be, depend on your system (settings), so the limit we have set for the largest file is set on a level witch properly is above what most systems could handle. Clipping large files will avoid Xruns produced by the convolver. There is no difference in that behavior between LV2-IR, jconvolver or guitarix-convolvers. It is up to the users to find there own limits.

The amp-heads, use all the same algorithm to emulate the tube responses, there is just a difference in the used array tables, so it is unlikely that a special amp-head will produce Xruns, were a other didn't.
Anyhow, setting the amp to ------ will simply disable (switch off) the amp-head itself and is included to use guitarix as a plain effect rack.

Also, make sure you use the last release, witch is at the moment 0.23.3, or even better, use our GIT version, and, if you build it by yourself, use the --optimization configure flag, to make sure all your CPU features are supported.

If you use qjackctl you could make jack more verbose to get information about witch app produce the Xruns.

Anyhow, if you really could indicate a source of trouble in guitarix, we are interested into hear about and trying to reproduce it.