Need help

[Qualitymix]

Okay guys here's the deal. I got a new system, Dell Optiplex 980. It's got an Intel i5 @ 3.0ghz and 4gb of ram. I've got an nvidia gt 520 graphics card and an maudio delta 24/96 sound card. Also, a PCI firewire card for my Mackie Onyx Firewire mixing board.

I've tried KXStudio, Ubuntu Studio, AV Linux, and they all do the same thing. When I turn jack on, I get one xrun every like, 10 seconds.
It is clearly a kernel/hardware issue, because this behavior is exactly consistent across many setups and settings.
Thing is, it only does it when I'm using the MAudio delta card. If I use my Firewire option, no problems. Onboard audio? No problems.

I've investigated the possibility of it being an IRQ problem, but is there a sure fire way to track down the exact cause of an xrun?

[briandc]

Have you tried using the QuickScan app? That will tell you a lot about your settings, and may help narrow-down the problem. If not, you can find the QuickScan install instructions here: https://github.com/raboof/realtimeconfigquickscan Make sure you have perl and mercurial installed first.


brian

[Qualitymix]

Yes, I did run that script. There were maybe one or two issues that came back, but nothing major I thought. Not to mention, I thought avlinux and studio were both already tuned for realtime.

[asbak]

It may be an issue with the PCI bus (The M-Audio Delta is PCI?)

Your motherboard presumably has a PCI Express to PCI bridge (not native PCI) which may be providing subobtimal performance.
There may be settings in BIOS which could help with this or alternatively you could try experimenting with PCI Latency timer settings on the terminal.
Check whether any IRQ's are being shared with the audiocard & PCI bus. If so, disable those other devices. (Could be some USB ports, Ethernet ports etc). Changing PCI slot can sometimes help to resolve such issues.

Check the usual stuff for example that you're using a PREEMPT or RT Kernel, that your CPU frequency scaling is set to Performance and so on.
Poor harddrive IO performance will also cause Xruns, poor PCI bus performance (slow IO) will do the same.

If you're unlucky then it could be that the PCI performance on the MB is just not good enough in which case there's not much one can do to salvage the situation afaik.
The Asus P9D-X motherboard works OK for me with a RME HDSP PCI card but I ended up disabling one of the Ethernet ports and use a self-compiled PREEMPT kernel + Debian Jessie.

[English Guy]

Just a thought, try turning networking off. One of my laptops has xruns when wifi is on.

[Qualitymix]

Unfortunately nothing seems to be helping. I've used rtirq, I tried optimizing the PCI latency, nothing seems to work. Another part of the issue is that the realtime input is garbly. Sounds almost like a really low bit rate mp3.
The funny thing is, I plugged in my USB interface, and my system is apparently so WELL optimized, I'm achieving the lowest latency I've ever gotten with it! LOL


Any other suggestions guys?

[asbak]

Only other suggestion I can make is to run it on a different motherboard, either an older one with native PCI or experiment on a different brand modern board with a different PCIe to PCI bridge chipset to the one you're currently using. It's possible that some PCI bridges work better / faster than others.

Basic formula was
- Ensuring that there was no IRQ sharing happening with the PCI card and other devices
- Not using the RME's integrated MIDI ports for playing softsynths (these were strangely responsible for xruns, I have no idea why)
- Using a PREEMPT 1000Hz or RT Kernel
- Using fast drives
- The usual system tuning from the usual guides

[Qualitymix]

So I know that the card itself works fine, because I've been using it for years with little latency on an AMD motherboard. I have a new question now. Would finding an adapter to convert my PCIe slot to a PCI slot work?

[artek]

What about alsa? Can you play a music and record without jack on 1010?
Can you run jack with unplugged i/o box? Have you used envy24 control to setup hardware clock rate?
this command can help you to observe "realtime" irq polling

Code: Select all

watch cat /proc/interrupts

[asbak]

So I know that the card itself works fine, because I've been using it for years with little latency on an AMD motherboard. I have a new question now. Would finding an adapter to convert my PCIe slot to a PCI slot work?

Yes I doubt there's a problem with the card. My guess would be it's the different motherboard and its PCI slot. (Presumably bridged from PCIe)

It may be tricky to find an adapter which will fit and there's no way of knowing whether it will work until you try it.
The easiest fix may be to go back to the original AMD motherboard unless you don't have that any longer.

[Qualitymix]

It wasn't just a motherboard replacement, I replaced my whole system. Going back to my old MB isn't an option.

[briandc]

Unfortunately nothing seems to be helping. I've used rtirq, I tried optimizing the PCI latency, nothing seems to work. Another part of the issue is that the realtime input is garbly. Sounds almost like a really low bit rate mp3.
The funny thing is, I plugged in my USB interface, and my system is apparently so WELL optimized, I'm achieving the lowest latency I've ever gotten with it! LOL


Any other suggestions guys?

When you say "realtime input," is that midi input or audio input? If it's audio input, it might be your sound card. If it's midi, it might be the cable connection. Can you test performance on another machine and compare the two?


brian

[Qualitymix]

It would appear to happen on any audio output coming from that card, no matter the source. When I monitor just the Hardware inputs on the card, there's no garbling, but when I switch to jack monitoring, there is an audible difference. The high crackle/garble kicks in.