Reaper's CPU usage Exponentially Higher Than Other DAWs?

[JamesG5454]

Hi There -

Here are my specs -
Mac Pro (Early 2009)
Dual Quad Core Intel Xeon - 2 X 2.93
24GB 1066 MHz Ram
SSD Startup Disk

Issue: Reaper's CPU usage is exponentially higher than other DAWs with the same project setup (Bitwig, Ableton, Studio One, and Cubase) ? I feel like I have clicked and unclicked every parameter that relates to Reaper's processing engine, and yet nothing seems to have a large effect on the CPU usage.

Question: Does anyone have an idea of what could be causing the issue. Or has anyone been able to tweak the preferences within Reaper so it functions efficiently on an old Mac Pro? If so could you possibly share the settings?

Thanks for any help you can provide,

[serr]

Hey that's my Mac Pro.

I haven't found a way to max this out with audio work yet. I did have a settings issue a few years ago that I solved. I was hitting the wall with a project that was over 200 tracks and just as many plugins.

Hyperthreading off (Reaper prefers to manage its own threads)
Set number of audio processing threads from 1 to 8 (the physical number of CPU cores)

I use some 3rd party plugins that it turns out are not compatible with Reaper's Anticipative fx processing feature. I disable this for any track with one of those plugins inserted. Do NOT disable AfxP globally in preferences though! Only per track for incompatible plugins.

Now there's no back wall. I can run mixes with stupid track counts and hundreds of hungry plugins. It took some screwing around to figure this out because any project smaller than that ringer that came along shows no signs of trouble even with some completely wrong settings. I was running live sound with a low buffer for < 11ms round trip latency with 36 live input channels for a couple years before correcting those settings and never had a glitch there. (FYI I run a 1024 sample block size for headroom for studio work where there's no live monitoring.)


I do understand there are a few modern MIDI instrument plugins that can bring even an 8 core i7 to its knees. I don't play with MIDI instrument stuff so I'm out of the loop for that.


What are you trying to run?

[JayJSE2]

Originally Posted by serr

Hyperthreading off (Reaper prefers to manage its own threads)

Is this an option inside Reaper, or for the whole of macOS? I can't seem to find it anywhere.

And how can you tell whether plugins are compatible with anticipative fx or not?

[Xenakios]

Originally Posted by JayJSE2

And how can you tell whether plugins are compatible with anticipative fx or not?

If the plugins use external DSP hardware like the UAD or TC plugins, then it won't work. Occasionally there have also been problems with plugins that run on the CPU, but it just has to be found out on a case by case basis. (Basically, if the plugins work when doing faster than realtime renders, they should work with the anticipative processing too.)

[serr]

Originally Posted by JayJSE2

Is this an option inside Reaper, or for the whole of macOS? I can't seem to find it anywhere.

Hyperthreading is a firmware level setting and you can access it through the following command in the Terminal:

sudo nvram SMT=0

To re-enable hyperthreading, use the command:

sudo nvram -d SMT

Changes take place on a reboot . . .

Originally Posted by JayJSE2

And how can you tell whether plugins are compatible with anticipative fx or not?

The usual telltale is crashy behavior (acting like the machine is maxed out) but Activity Monitor shows nowhere near maxed out (not even a single core). Sometimes you DO see increased CPU use too but when you know it shouldn't be expected.

When that happens, go and disable AfxP on that track. 9 out of 10 times that clears it up. I find Universal Audio and many Waves plugins are notorious for crashing AfxP.


PS. Sanity check with the basics:

What are you controlling sample rate and block size for the system with? The Reaper Preferences/Audio/Device page? (Boxes checked and values entered.) or some other audio app or control panel app (Boxes unchecked to allow/force that in the Reaper page.)

You're not running different sample rate sources in the same project and live sample rate converting? (Makes for high CPU use.)

[Xenakios]

Originally Posted by serr

You're not running different sample rate sources in the same project and live sample rate converting? (Makes for high CPU use.)

Especially if the resampling quality option is set needlessly high...

[Arpegia]

about the Buffering Setting, I found better result if I change the "Media Buffer Size" : default is 1200, and I set to 4000.

But my Mac pro is not the same, then you have to check.

After, the biggest difference is about the Hyper-threading. If i don't turn it off before loading Reaper, I have bad performances (clic and drop very soon).

With those to settings, I have the same capabilities (maybe more) than what I had few month ago with Logic Pro. Excepting the fact that Reaper is more stable and never crash.

[Arpegia]

Originally Posted by serr

Hyperthreading is a firmware level setting and you can access it through the following command in the Terminal:

sudo nvram SMT=0

To re-enable hyperthreading, use the command:

sudo nvram -d SMT

Changes take place on a reboot . . .

I don't like to use the terminal (I never use it) . It easier to turn off hyper threading with (Apple store Free ) Xcode (instruments) You load it, go to preference, turn hyper threading off and that's all :-)

[serr]

Originally Posted by Arpegia

I don't like to use the terminal (I never use it) . It easier to turn off hyper threading with (Apple store Free ) Xcode (instruments) You load it, go to preference, turn hyper threading off and that's all :-)

The Terminal is a pretty important and useful utility. It's not something to avoid! You'll have to reset hyperthreading back off after a restart with the preference setting. The terminal command sticks until you change it back.

The media buffer setting needs to be that high running from a SSD? That's odd. You should be able to run that at 200ms with a SSD. I keep mine at 600ms for faster seeking for editing (I'm impatient).

What block size are you running? Are you doing low latency needing live sound work or live performance through MIDI instrument plugins? Or are you just recording and mixing? This is the biggest deal setting. Low latency settings for example, limit your processing headroom. If you inadvertently set this low when you weren't actually running live sound it would be like trying to drive on the highway in first gear.

[JayJSE2]

Originally Posted by serr

Hyperthreading is a firmware level setting and you can access it through the following command in the Terminal:

Thanks! But before I go ahead and do it, how does turning it off affect the rest of mac os and any other programs running on it?

[Arpegia]

Originally Posted by JayJSE2

Thanks! But before I go ahead and do it, how does turning it off affect the rest of mac os and any other programs running on it?

Good question. I was anxious about that too. It's why I prefer to turn it off manually with Xcode, because when you restart your Mac it goes back to the initial setting.

[Xenakios]

Originally Posted by JamesG5454

Issue: Reaper's CPU usage is exponentially higher than other DAWs

How are you measuring it? And are you actually having some audible problems (skipping, glitches etc) due to the assumed high CPU use?