Also, tested a bit with the most demanding VST instrument in the song. On the Spectrasonics homepage they state, that one instance of their VST will use only one CPU (i’m not sure if that’s usual for any VST), so i created one instrument per voice. But neither did this change anything: It seems that the same CPU gets assigned to all instruments.
BIOS updated, PC still works. But Renoise still only gets one CPU’s power…
Double-checked the BIOS settings after updating and didn’t find anything that i’d assume would keep Renoise from using all cores. Then again many of the CPU related advanced settings in the BIOS - and there are a lot - i do not really understand. The ACPI settings are sparse (e.g. i cannot configure anything about processor parking anywhere in the BIOS) and in the CPU settings it is set to use all cores (which seems to work fine, at least the Task-Manager shows activity in all CPU’s, but not from Renoise).
If the conclusion is that the other programs that handle multiple threads of CPU work correctly (use all the cores), but Renoise only uses one, is that something happens with Renoise and that generation of CPUs (some incompatibility). You just have to compare the behavior with other software under the same operating system. If another software works well with all the cores and Renoise only uses one always, there you have the problem.
I assume that you use the view of logical processors in the Task Manager and you use the Resource Monitor to see the changes in the use of multiple threads …
Play a simple song, with 8% of CPU use in the Renoise marker.
@stoiximan Thank you! Just downloaded, installed and configured Asio4All, but no change.
However, looking to the CPU stats with Performance Monitor, with only Renoise selected, there is indeed activity on multiple cores. Thanks Raul!
Here a screenshot as suggested:
In the “song” used for the screenshot i’m playing one track, playing the notes rotating between 4 Omnisphere-instruments, each with the “Analogue Drama” patch (very expensive patch) and each limited to 2 voices (default is 8).
On my old PC i used one Omnisphere-instrument with this patch, and 8 voices and the engine didn’t stop. My attempt to explain: The old PC was an I5, i’m not sure how many cores it had, if i am not mistaken there were 4, and no logical processors. And the CPU was overclocked. And thus one core of my old PC was more capable than one of the logical CPUs of my new rig.
What contradicts either my above explanation or my earlier assumption that an instrument is a VST instance: Even though i’m using 4 Omnisphere-instruments, the load is primarely on CPU 9 (screenshot). Do i need to instantiate the VST in a different way? Like duplicating the DLL instead of creating multiple instruments from the same VST? I will give this a try.
(Side note: Tested the core usage with CPU Z stress test. All ran on maximum.)
I know of 2 other things breaking renoise multicore support.
One ist renoise can only spread load if there are different tracks. One track per core, one instrument per track - seems to be the optimal way of setting up things.
The tracks seem to be calculated in the same core, if parameters in them are interconnected i.e. with hydras, signal followers etc. These can be moved to send channels to make the underlying tracks work multicore again.
Yeah and it could be possible that a VST will establish some sort of main process on their first instance load, and all following instances will feed it with data to make sounds. Many VSTs use this feature to actually make better multicore action, but I could very well imagine that something went wrong™ and the process is somehow nailed to a single cpu, by renoise or by configuration of the VST or elsewhere. Have you tried sandboxing the VST?
As it seems in your screenshot, you just not use a large percentage of each thread because Renoise does not need it at that time. In fact, you are using up to 9 threads at a time at the time of screen capture.