High CPU use on OSX with many loaded, but idle tracks

[rsing]

Hi,

I've been using Reaper for a while on Windows (on a 2012 ASUS box with i7 and 10GB RAM), but switched recently to a Macbook Pro 2011 with 16GB RAM, SSD and i7 CPU running Yosemite (recent, clean install).

When running the most excellent RS5k-based drum kit "SM drums" on OSX I noticed something strange. After the kit has loaded (which takes some time and resources), the Reaper CPU use remains high according to Activity Monitor, even though nothing is playing - it stays on 8-10% (it reads 36-40%, but this is because each core is measured as 100%). On Windows the CPU use drops to <1% after the kit has loaded. Just listening to the fan noise, it is clear that Activity Monitor is more or less correct in its estimate. Removing each track in the kit one by one slowly reduces idle CPU use until no tracks remain and the total CPU is as it has been on Windows the whole time (<1%).

When playing the SM drums demo track, OSX CPU use rises only slightly compared to the idle use, but OSX use more resources than Windows also when playing.

At first I thought this was related to RS5k, but the same thing happens regardless of instruments. Adding any virtual instruments to a new track increase CPU use in OSX even when it is idle, as far as I can tell. Of course I am curious as to why this happens. I only have one Mac so I can't verify that this is not related to my unit, but it should be easy for any one of you to check. If it is the case, can anything be done (is it e.g. related to Yosemite)? I would prefer idle tracks not to affect the resources available to such a degree, as like to have my whole project (with all tracks) open, even though I only have certain tracks active. Any ideas?

Regards,

Sing

[vanhaze]

Sorry, i can't help you with your issue.

However, would like to know also what the h*ck is going on in your situation.

I am also on OSX 10.10.3, using Reaper 500pre29. (64bit)
Can you maybe sent your Reaper Project, so i can check if your issue also appears for me ?

[cfillion]

I'm seeing a similar behavior on v4.77. The CPU usage when idling seems to be directly related to the number of tracks in the project.

On my computer (iMac with OSX 10.10.3), any project consisting of 200 empty tracks will consistently use around 11% CPU when idling (or ~94% of a single core as reported by OSX's Activity Monitor).
Muting all tracks does not lower the CPU usage ("Do not process muted tracks" is enabled in REAPER's preferences).

Real-life project: https://i.imgur.com/hkHTPuY.png
Every 217 tracks excepted the two samplers are reporting a 0.00% CPU usage, yet REAPER is using a lot more.

The CPU usage only drops when the audio device is closed by focusing another window. Switching it to "<none>" has no effect.

[rsing]

Hi and thanks for your reply!

Perhaps the easiest way to reproduce it is loading the standard project from:

https://smmdrums.wordpress.com/category/reaper/

Use the download link under the subsection "SM MegaReaper Drumkit". There you will find the Megareaper project. Just load it and you should notice the issue.

And of course I should have added that I run Reaper v4.77/64.

Sing

[rsing]

Originally Posted by vanhaze

I am also on OSX 10.10.3, using Reaper 500pre29. (64bit)
Can you maybe sent your Reaper Project, so i can check if your issue also appears for me ?

Hi VanHaze,

Have you been able to check if this problem is present in Reaper 5 as well?

rsing

[vanhaze]

Hi,

I downloaded the Reaper Project, opened it and have let it been idle for more than 1 hour.

Outcome: Totally NO increase for me in CPU usage.

- Total CPU readout keeps slightly fluctuating between 2.8 and 3.1
- RT CPU readout keeps slightly fluctuating between 3.9 and 4.4

Test facts:

OSX 10.10.3
Macbook pro early 2011, CPU: 2.2 ghz I7, 8 gig RAM, Crucial CT960 SSD
Audio interface: Apollo Twin, via thunderbolt.
Buffersize: 512
Thread setting: Relaxed.
Reaper 50pre32 - 64bit version.
No other apps were open during idle test Reaper.

[rsing]

Originally Posted by vanhaze

- Total CPU readout keeps slightly fluctuating between 2.8 and 3.1
- RT CPU readout keeps slightly fluctuating between 3.9 and 4.4

Hi VanHaze,

Thanks for this. I installed Reaper 5 Pre32 and retried using SM Drums. It has indeed improved significantly - it has gone down from 36-40% to 10% in Activity monitor. This is *very promising* as the heat generated is below the threshold where the Macbook starts to heat up and generate fan noise!

Reading your CPU values - where did you get your readings? Can't find RealTime CPU in Activity monitor.

Thank you!

rsing