Reaper: Massive rise in CPU usage, why?

[ghostwhistler]

Not sure what's going on here.

I have a piece and I have frozen all the parts so as to minimise cpu usage from softsynths/fx etc. When I play it back in the DAW the cpu usage is minimal and perfectly acceptable, barely 5%.

When I came to render the whole it got up to around 80%! Why is this happening?

Reaper was the only software running. I have not had this problem before. I've no idea what caused it, whether it's particular to this project. I'm not using vst's I don't normally use. Even freezing parts to audio didn't ease it off.

I hope this isn't how it's going to be moving forward otherwise I'm going to have a problem.

I'm using the current version of Reaper in Windows 11. I can run it normally just fine. Fortunately, as everything was frozen beforehand, it took no time to render. but still

[Scrubbing Monkeys]

That seems normal....if I understand correctly. Reaper has always taken ss much cpu as it can when rendering. If you compare it to others it renders a bit faster. I think that is why the high cpu.

[No_Use]

Yes, as said above, assuming you're rendering in 'fullspeed offline' mode, it's faster than realtime and Reaper tries to use as much CPU as possible.

[ghostwhistler]

That seems normal....if I understand correctly. Reaper has always taken ss much cpu as it can when rendering. If you compare it to others it renders a bit faster. I think that is why the high cpu.

If its normal then why has this never been the case before? To the best of my knowledge i have altered no settings, I don't even know what half of them are in the render window. So far it has been fine, it renders quciker when working from audio files (frozen) rather than direct from the softsynths/fx. But it has never rendered in realtime. A five minute track took roughly a couple of mins and never used anywhere near this much CPU, so something must have changed. I have the latest version of Reaper and that was working fine

[ghostwhistler]

Yes, as said above, assuming you're rendering in 'fullspeed offline' mode, it's faster than realtime and Reaper tries to use as much CPU as possible.

That is mode, though it would have been the default setting since I have never knowingly changed it. I had no need to. Now it's using monstrous amounts of cpu for some reason when it didn't before

[funky lime]

if you accidentally rendered parts to a different sample rate than the base project setting, or if any of those files are time-stretched or pitch-shifted in any way, it will munch a lot more cpu when parsing them. also maybe include exceptions for reaper and your audio folder(s) in windows defender?

[Kr3eM]

Any updated plugins that may have new option added or reset previous settings and now use heavy oversampling when rendering?

[No_Use]

To be honest, I'm not sure what the problem is.
Because (as said before) generally: more CPU use during offline render: faster rendering
And you can't use Reaper anyway during render, so what bothers you?

[kmonkey]

To be honest, I'm not sure what the problem is.
Because (as said before) generally: more CPU use during offline render: faster rendering
And you can't use Reaper anyway during render, so what bothers you?

Exactly. Every DAW behaves like that. I think he's heavily confused. Or the case is not explained correctly.

[ghostwhistler]

Screenshot (8).png

Ok. I don't think this situation is right. Look at this screenshot and tell me that getting huge readings of cpu usage like this is normal. It has never been this high before. So why is it all of a sudden saying this? Don't just accuse me of being 'confused' because that doesn't help. I'm not a technician, I just want to make music, and I don't understand what is happening.

Screenshot (6).png

Screenshot (8).png

[BertKoor]

Am I not seeing what ou are seeing?
16 or 19%... You call that HUGE?

Have you checked your render options?

Screenshot 2025-03-07 at 12.03.50.png

You could have changed something. So what, it works. Move on...

[Kr3eM]

What soundcard do you have? and do you have the option to run ASIO instead of WASAPi ?

[kmonkey]

Screenshot (8).pngOk. I don't think this situation is right. Look at this screenshot and tell me that getting huge readings of cpu usage like this is normal. It has never been this high before. So why is it all of a sudden saying this? Don't just accuse me of being 'confused' because that doesn't help. I'm not a technician, I just want to make music, and I don't understand what is happening.Screenshot (6).pngScreenshot (8).png

Well, in all fairness, it was you who "accused" Reaper of increased CPU usage - the fact is this is not the case. And yes, I have Diva, and no, I don't have such CPU fluctuation.

So yes, you are confused because you started accusing DAW of the lack of your shortcomings.

We helped you by confirming that this is not the normal behavior and that this is not a Reaper issue. That alone should get you on the right path. Do not expect people to fix issues you caused yourself by setting up your DAW or drivers, or something else incorrectly.

Trust me, it will go a long way if you sit and invest time. You do not need to become a "technician," but you need to know your tools instead of going online and blaming apps.

Good luck.

[ghostwhistler]

Nothing has been 'confirmed'. Nor have I made 'accusations'. It's a piece of software and this isn't a jury trial. What a weird response. I have no idea why cpu usgae is spiking, do you? Clearly it isn't normal, if it were it would have ever been thus. The DAW is the most likely cause since these spikes do not happen with specific vst's nor do they happen when I run vst's standalone outside of the DAW (those that can). I'm unclear why drawing the most rational conclusion is a bad thing.

I'm not sure what 'investing time' means. In what? I don't know what the problem is, that is why I came here and asked. If you have answers, please share them. Otherwise this is just unproductive. I have no idea what you mean here

[ghostwhistler]

Am I not seeing what ou are seeing?
16 or 19%... You call that HUGE?

Have you checked your render options?
Screenshot 2025-03-07 at 12.03.50.png

You could have changed something. So what, it works. Move on...

No settings have been changed.

My last post isn't referring to rendering. I think you've misread what I posted. I am seeing cpu spikes that were never there before. Just telling me that you don't think 19 is a big number does nothing to address why this is now happening. Why is this happening? Why is Reaper now suddenly telling me my vst's are using 4x as much CPU as before? Do you know?