[LAD] Has anyone ever played a plugin in realtime ... [related to:] hard realtime performance synth

Emanuel Rumpf xbran at web.de
Sat Feb 6 20:36:20 UTC 2010

2010/2/4 Jens M Andreasen <jens.andreasen at comhem.se>:
> Zap the Gnome on steroids and dedicate your GPU for audio then!

How to ?
Where is the switch that would tell ladspa/dssi to use the GPU for processing ?

> I have success with 3 audio buffers в 0.3 ms + another 0.3 ms for the
> PCIe roundtrip to the GPU. Voicecount is well into the hundreds and then
> some ...
That sounds marvelously.

I found this information for DSP Accelerators

as well as this interresting device:
(I assume that it's not supported on linux)

Those just work with special code-adjusted plugins.
Does the VST API support them or even use them if present ?
Do the RMI devices have plugin-accelerating DSPs ?

Would it be worth to design an open-hardware DSP-add-on with an open API ?

Since GPUs are very common already and have the fast PCIe connection
using them may be more appropriate, I think.

Running the rt-check script, indeed, I found some issues.
Fixed them.

Now, the only remaining warning is:
Checking for Generic PCI bus-master DMA support... not found.
** Kernel without Generic PCI bus-master DMA support

I retested with an undemanding 130 MB piano gig-file.

- Linuxsampler runs stable at 8ms. Great.

- I'm able to play fast Sequences with PianoTecTrial at 16ms.
  I'm not allowed to use sustain or play quick chord progressions.
They produce xruns and hard noise then.

- yoshimi 054-pre4 behaves comparable to PianoTec at 16ms, but slightly worse.
  It produces occasional xruns even without chord-progressions.

Likely conclusion:
My system is not fast enough for this kind of processing,
or somehow has a bad hareware-design.
I will buy a new machine next year with 8 processors hopefully...

Until then, the GPU seems the only miracle that could possibly help me out.
Would it ?

Thank you, replyers, for your replys and suggestions.


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