Renoise 3.1 - CPU usage getting wild

Take a look at screenshot below and you’ll notice Win10 taskmanager CPU usage is 3% while Renoise 3.1 is showing around 30% CPU usage.

7851 snap.jpg

In this situation Renoise 3.1 x64 is playing song without any VSTis, only standard samples and standard effects from Renoise 3.1.

No matter what type of instruments I use (samples or VSTi) - CPU usage in Renoise is always to high.

Instead of DirectSound, I tried Asio, but I get around 20% CPU usage in Renoise, while Win TM shows 4%.

This CPU usage problem is happening only on my new configuration: Intel Z270, I7-7700K, SB-Z, Win10 x64, 24-bit 96kHz stereo:

7852 snap2.jpg

Never before happened with older HW configuration (Intel X58, I7-950, Win7 x64, Creative X-Fi) with Renoise 3.0 and same songs.

I already reinstalled Creative drivers, do you have any other ideas how to fix it?

Have you tried disabling CPU throttling? (For me this means plugging in your laptop and selecting High Performance plan…)

http://isboxer.com/wiki/HOWTO:Disable_CPU_Throttling_in_Windows

Mostly: Does it affect playback? If no thenjust ignore it.

This situation does not seem to make any sense.Actually, to be reasonable if it should be the other way around.The percentage of the Windows panel is the sum of all the programs in use, included Renoise.I have no idea how Renoise calculates that percentage, but compared to the Windows panel, I’ve never had any matches.

For what it’s worth the screenshot:

7854 renoise-cpu-use.png

I use a similar machine:

  1. CPU: i7 6700K
  2. 32GB RAM
  3. Sound Blaster ZxR
  4. Windows 10 x64

Here I use several VSTi…

Edit: I use Sample rate = 192000, and Latency = 35 ms, that consumes many more resources…

Have you tried disabling CPU throttling? (For me this means plugging in your laptop and selecting High Performance plan…)

http://isboxer.com/wiki/HOWTO:Disable_CPU_Throttling_in_Windows

Mostly: Does it affect playback? If no thenjust ignore it.

Your advice to change power options from balanced to high performance - fixed it.

However, downside is that CPU is now locked to max speed (4.38GHz - from screenshot) in Windows and has no power saving Throttling options (as it can bee seen in first post where CPU was currently 1.01GHz, but not locked).

The next screenshot is proof - taken with ‘High performance’ enabled in power options:

7855 high performance.jpg

As it can be seen on screenshot, CPU usage is 7% in Win Task manager while Renoise detects 9% (much more accurate - in comparison to screenshot from the first post).

To answer your second question - when ‘Balanced’ is enabled in Win power options (as most people probably defaultly has) and when ‘Overload prevention’ in Renoise is enabled (as it is configured in screenshot from first post) - I have had problems in some occasions with playback when Renoise CPU usage reaches 95% (while Wndows task manager shows around 25% and CPU didn’t yet ‘throttle’ core speed to something higher).

To conclude - seems like CPU usage calculation routine in Renoise is not using the fixed base speed of CPU (like Windows task manager do) - instead is using only current (variable) CPU speed. This is what probably gives a wrong (unusable) CPU usage information on Renoise screen and this is what is probably related to Renoise playback problems (in some occasions) if ‘Overload prevention’ is enabled.

If im not wrong with this - I really hope it will be fixed with next version of Renoise, cause faster processors are coming and we wanna save the power and the Earth :slight_smile:

Seems like CPU usage calculation routine in Renoise is not using the fixed base speed of CPU (like Windows task manager do) - instead is using only current (variable) CPU speed. This is what probably gives a wrong (unusable) CPU usage information on Renoise screen and this is what is probably related to Renoise playback problems (in some occasions) if ‘Overload prevention’ is enabled. If im not wrong with this - I really hope it will be fixed with next version of Renoisecause faster processors are coming and we wanna save the power and the Earth

This is interesting. I agree.

I think renoise calculates its cpu usage by the time spent in processing the audio graph vs the waiting time until the next block has to be processed. Of course cpu scaling will mess with this value, as lower clock rates will mean longer time until everything is processed.

Also this way of calculating cpu usage will also depend on multicore processing, not every song/setup can fill out all cores, sometime processes still have to wait for others to finish.

It does make sense however vs a cpu monitor, as you will see the real resource usage of your tune, and how much slack room you really have in your project. the 80-90% glitch mark will be clear to see, even if real cpu usage is only 30% because your song cannot be calculated in parallel because of its track structure. only the cpu scaling glitches are misleading with this approach, but I think it would be nontrivial to take into account. I can understand it being incinvenient if you drive renoise on a laptop with high latency. Normally realtime low latency audio workstations should disable cpu scaling by default for audio work.