Update 2.4.1 to 2.5.1, massive CPU hit, crackling.

Today I updated VCVfree from 2.4.1 to 2.5.1 When I open my patches I get 100% CPU spikes, crackling sound. I use the same cpu and sound settings as in 2.4.1. Anyone experiencing more CPU usage in 2.5.1 ?


What system/OS are you using? I’ve only tried it quickly, but seems fine on old i7 laptop from 2019 and Windows 10.

1 Like

Yes, i have the same issue on my linux Linux USER 6.6.13-gentoo-x86_64 #1 SMP PREEMPT_DYNAMIC Fri Mar 1 10:49:26 CET 2024 x86_64 AMD Ryzen 9 5950X 16-Core Processor AuthenticAMD GNU/Linux

patch from yesterday on 2.4.1 about 80% same patch on 2.5.1 has now 139% and above

not useable

so i’ll go back to 2.4.1

1 Like

so back on 2.4.1 Patch works well on 80%

1 Like

Yes, I see a significant jump in CPU usage on Windows when going from 2.4.1 to 2.5.1.

It hasn’t caused problems for the patches I have tested… yet. There were very few patches my computer couldn’t run with 2.4.1, but I am afraid I will be bumping up against the CPU limit much more frequently with 2.5.1.

1 Like

This would be a PITA to test but it would be very interesting to know if the CPU hit also applies to 2.5.0. Assuming this is associated with a new feature (as opposed to a pure performance regression) there aren’t a lot of likely suspects in 2.5.1 but there are several in 2.5.0…


OS: Win 10 CPU: 8700K GPU: 1050TI RAM: 32G

1 Like

Same issue here: quite the performance hit when updating from 2.4.1 to 2.5.1. Windows 11, Ryzen 5 5600X, 64 GB RAM, RTX 3050.

1 Like

Hi all, would you please contact us via https://vcvrack.com/support with this information so we can look into the matter?


Same issue here. MacBook Air, Apple M2 Chip, 24GB, Sonoma 14.4.1. I found out, if I reduce the threads to 1 or 2 the crackling is apperently away but mouse movements can bring it back. So more Threads so more crackling. So more threads cpu usage is growing up.

1 Like

whew, glad i saw this thread. i will wait to update mine… i use M1 macbook…

1 Like

I’m having the same problem. My previous patches are now melting my system down.

will a new thread be made when the bugs with the latest 2.5.1 update are fixed? im scared to update still

If there’s an updated release, there’ll be a new announcement, and these always include a change log.

I hate to say that I’m with the group on this. With Rack loaded and no modules at all according to the Task Manager it is using 38%. This is on an R9 Win10

How can I roll back?

@shofb , all previous installers are at listing directory /downloads/ (nope: see below) – a simple uninstall and reinstall should work. Baffling that the overhead is incurred even with no modules loaded. If I have time over the weekend I’m going to poke through the Github commits, compile some intermediate versions, and see if I can diagnose this, though I hope it’ll get fixed soon. If I find anything I’ll send observations over to support in furtherance of that objective.

Is anybody not having problems with 2.5.1? Also, I know 2.5.0 wasn’t around very long because of the ParamHandles bug, but is anybody willing to give 2.5.0 a try and assemble a few data points? If the problem exists in 2.5.1 but not 2.5.0, that’s a much smaller search space.

Hello Everybody, I installed 2.5.1 and so far don’t see any issues. My old patches work just as before the update - no CPU jumps, no audible crackles.

My computer is very old Lenovo ThinkPad X230: Intel(R) Core™ i7-3520M CPU, RAM 8.00 GB, build in Intel HD 4000 graphics (no GPU), Windows 10 Pro 22H2. external monitor 1920x1080. VCVRackFree 2.5.1, single tread, 10Hz framerate, WASAPI driver (48kHz/256ms).

Is it possible something to be related to the GPU handling ? Will be interesting to hear from another user with no dedicated GPU…

1 Like

I don’t see rack pro only rack free… will it update?

oh, good point, sorry–I just assumed both were in there.

If you log in to the website, look for the Rack Pro download link, and manually edit the version number, it should work (I was able to download 2.4.1 and 2.5.0 just now that way).

1 Like

I’m still waiting to update, I can’t handle a drop of performance on this PC until the end of June. finger crossed, then I will update.

1 Like