Unexplanable Cpu Overhead


I’ve ran into this problem:

the song I’m making these days, full of patterns (more than 60), which are full of tracks (13), which are full of columns (35 in total) which are full of notes from 16 VST instruments and effects from various DSP’s, suddenly has started behaving unexplicably: the CPU just runs over 99.9% at the beginning of the song, and there is nothing I can do about this :huh:

Luckily, the autosave function saved a version some minutes before, which works right. it is nearly the same song! just a couple of patterns and a delay were added! :ph34r:

muting tracks, removing instruments and switching from ASIO to DSound and viceversa did not help in any way to understand the cause of this.

So, has anyone run into this before?

I can continue my song by using the backup, but I would really like to understand what was going on :blink:

PS: it does not look like P4 denorm problem, since it never occurred before, and I’m using the same VSTi’s I was always using before
(Pro 53, kontakt & kompakt based stuff, Z3ta+, Trilogy, Realguitar…)

The song takes about 1.3GB of RAM (!!). I only have 1GB, but it worked flawlessly with HD swapping until this problem occurred (except for the need of playing the whole song once, before being able to listen to it without crackling :D)


Have you tried to redo the things that you did that made the track lock up like that. I mean, take the backup, and try to recreate the high cpu usage. Did you add any instances of anything?

Maybe it’s a third party software conflict? Did AV software or something start scanning at that instant?

Bugs like that are the worst in software - very hard to pinpoint, at least in the type of programs I work with.

I suspect it might be a threading issue.

I’m revisioning the backup version.

It’s pratically identical to the troubled version, except for a couple of patterns (which were the clone of another one I had created some minutes before; consider that the autobackup saves every 10 minutes) and a built-in delay.

The latest VSTi I’ve added was Slayer 2, but it has been also added on the backup version. When Slayer plays in the backup version, the CPU rises at about 80% but the song flows on, while in the other version the CPU is at 99.9% since the beginning.

Don’t know… I will try to delete all VSTi’s except that playing in the first pattern and will submit it to bugs mailbox

This kind of worries me since my tracks are starting to become very large and complex too.

Hope the devs can figure out what’s going on!

You might not only need more diskspace, also systems like Serial ATA.
Renoise becomes a core application processing more data simultaneously than one of the bigger database engines does.
And those engines run on fat server systems. (As you also see in the professional audio world: there are special servers being created for the sole purpose of music composing)

I already own 2 SATA HDDs.

the problem is not on HDD side, though.

The instrument which overheads the CPU is PRO-53, which is a non-samplebased synth.

It something weird on the song and I’m unable to isolate it.

Go figure… I will keep on making the song from the backup copy :)

of ocurse you should try different ASIO buffer sizes.

If you experience that the sound gets choppy even at low CPU usages, you should try to increase the buffers size.

Also, did you try setting that “0” value for Absynth too?

I did not resolve my problem with that song: I just started using the backup song and I’ve never had that problem anymore, which I then think is somehow related to something wrong in the file.

Maybe something is different in the configs… like sample rate, UI frame rate or so…?

The old config should still be available in the document and settings folder somewhere, so maybe you can see if you find any obvious differences.

Line 47:

What Audio Latency (Buffersize in Samples) do you use ? Is the problem fixed by increasing the Latency ? What latency do you used in older releases (where you said that you had no such problems) ?

Have you enabled MIDI sync (as MIDIclock master) or use now somehow more MIDI than before ? (MIDI might decrease Audio performance with bad drivers).
Check in the MIDI configs that everything that has todo with MIDI is disabled.

Have you installed any new drivers or applications that maye run in the background ? Could be even a virus, eating CPU performance. Open the taksmanager an have a look if there is something stealing CPU performance.

Does this happen with all songs or just some specific ones ? Try some songs without any VST instrument and effects and let us know if the problem might be somehow VST related.

If nothing of this help, I could send you a renoise beta 1 build, to let you test if really the new release is the cause or something on you computer has changed ?