ForumsSoftware ← Slow plugin UI issues

Hi Randy,

First of all; thanks for the amazing software.

For a long time I haven't opened any of your plugins (maybe not even on my current machine at all). I just tried opening Aalto, but the UI is extremely slow responding. Even the time display in my Logic is slowing down when I open it. The CPU is not massively changing though. I also opened Virta and Kaivo to see what happens, and it's also occurring there. Other (CPU-heavy) plugins or synths I am not having any problems with. Do you know what might be causing it?

I am using Logic 10.5.0 on a 15-inch 2019 Macbook Pro with the 2,3 GHz Intel Core i9 processor and 32 GB 2400 MHz DDR4 ram. I updated to the latest Aalto version, but the version I had before (it might be 1.8) had also the problem.


Hi Erik,

Sorry you're having trouble. I have another report about slow graphics and I'm very interested to track this down ASAP.

What operating system are you using?

Can you confirm you are on the latest version of Aalto, 1.9.2?

Can you give the Aaltoverb demo a try and let me know if it has any of the same issues?

Hi Randy,

I am using Mojave (10.14.6) and indeed using Aalto 1.9.2 (but it also occurred on a 1.8 version before I updated to the newest version).

Just installed Aaltoverb and it's working smoothly and all fine.

When I open Kaivo (FL Studio, Catalina) the waveform display stays blank and tends only to appear after loading in another wave, iirc a similar thing happens with the vocoder display in Virta.

Thanks—I appreciate the feedback. This is a different issue I'm working on:

Thanks for the additional info Erik—it's weird how I still can't duplicate this, even though the setup I'm often using is so very similar—Mojave, MBP.

When you get a chance, if you are willing to, please give the latest Logic Pro a try and let me know if anything changes. Meanwhile I'll puzzle over the code.

I will! Thanks Randy.

I updated to the latest Logic and sadly still no improvements whatsoever. To make the problem even more visible, I screen recorded a bit. Notice for example the time display in the top when I open and close Aalto. Also in my dragging of a slider and other visuals inside the plugin you can see it's really buggy.

Thanks for making the video. Of course I see the problem. Unfortunately it's totally baffling right now. I have basically the same setup on Mojave, on a less powerful Macbook Pro, and it works totally smoothly.

Also unfortunately, there's no crash log to look at so I have no obvious point of failure.

A way I often stress-test CPU use is to turn the process buffer size down in the DAW to 16 or so. This usually generates clicks, but even so, the GUI stays smooth when I do it. So I don't think this is overall CPU related.

The only way forward I can see is to make some experimental version of the plugin that tries leaving out or changing parts of the graphics code so we can narrow this down. I'll send you an email when I have something.


I always used Aalto perfectly smooth on my previous laptop (Macbook Pro 2013-late), so for also me it's a mystery it's lagging on my current set-up. Any other plugin/VST is working perfectly fine.


I use JUCE for making audio/midi plugins.
And I think I had a similar issue before.
I don't remember the detail well, but I think it was caused by "setBufferedToImage".
If you use it, please try to remove them.

I remember that option and it's a promising idea. Thanks for writing.

Just wanted to add that I am experiencing GUI issues with both Aalto and Kaivo, whether loaded to the default patch or a super complex patch. I experience the same graphical slowdowns that users above note, but activity monitor shows 160% CPU usage when I just have the plugins open, with no tinkering, in the latest version of Logic pro. I have an 8th gen i7 in a 32 GB RAM mac mini, so I doubt the problem is the other users, I used to run both plugins extremely smoothly on much older hardware.

Love both synths so much, so any help is appreciated!

EDIT: Just in case it's of any help, I had some improvements after playing around with the scaling settings on my display!

Thanks for writing. I am pretty certain I have a fix that will help. I'm wrapping up the Windows build now and some other details.

I'm also experiencing extreme slow downs in Logic. The plugins are pretty much unusable. :(

Almost there...

Any update on this I'm getting the same problem with the Kaivo demo - was keen to buy from online demo, but I can barely run it on it's own in Logic to test. CPU is running v.high with just Kaivo loaded.

Logic 10.5.1
Kaivo 1.9.2
OSX Mojave 10.14.6
MBP 2016

Sorry for the delay—I've been wrestling with issues on the Windows side. Meanwhile you can download the Mac installer at

Thanks - although no noticable difference between 1.9.2 and .3 here unfortunately. Logic UI still unresponsive and CPU way up high with just Kaivo loaded. Will keep checking back for updates!

hmm. beta testers have reported a big improvement. can you please look in the upper right and make sure 1.9.3 really got installed? (no offense meant, but this happens)

and if 1.9.3 is running, please send me more details about your system via email. Thanks for your help.

working, nicely in cubase again.-thanks.

I have the same issue here with Virta VST on Macbook Pro hexacore i7 32gb ram 11.6.3 Big Sur running Ableton Live 11.1

The entire Ableton UI is slowed down when the Virta UI is loaded up, which is just as slow and stuttering, as if on 2 fps. I have version 1.9.3

My keyboard becomes less responsive when the Virta UI is loaded

Some combinations of computer and graphics card and screen scaling are particularly prone to slowdowns. It's possible you can find better settings.

First, turn animations off in the plugin's settings (gear) menu and see if the helps.

Next, you can try different Resolution settings in your Mac's System Preferences/Displays. The problem with some of these is that they draw a ton of pixels offscreen and actually downscale the result to the screen. So the hybrid software/GPU graphics engine of the plugins is really hurting.

Of course, just making the plugin window smaller may help, if you can use it that way.

I've finished a fully hardware-drawn graphics engine and will be rolling it out across all the plugins this year. This should fix all issues with slow drawing—meanwhile, I hope the tip about resolution settings can help.

Thanks, Randy.

I will try out all of your suggestions and report back!

There is a tiny improvement when I make the UI smaller, but it's still not possible to change values without excessive parameter jumps due to the laggy interface.

I had animations off already. When you say some combinations, does that include Macbook Pros? What else can I do to make Virta more usable?

Is there an ETA on the graphics redrawing fix?

Have you tried Virta without running other plugins at the same time? Virta is currently relying on the JUCE framework for graphics and when other plugins using JUCE are also open there can be big slowdowns. I'm switching to my own framework partly because of this. I don't have a release ETA right now.

Some of the first Retina MacBook Pros were the worst for this issue because they have big screens and relatively underpowered GPUs. What year is your machine from?

If you try all the 4 or 5 different resolutions that the system provides you with there may be one clear winner.

I definitely had only the Virta GUI open at the time, but will try the other options, even though changing my display resolution is not really a usable option for me.

My machine is a 2019 Macbook Pro 2.6GHz 6 core i7, 32gb ram, AMD Radeon Pro 5300M 4GB, Intel UHD Graphics 630 1536 MB and I'm running Big Sur 11.6.3 on Ableton Live 11.1.1 (latest version).


I understand that "use a different resolution" might not be a good fix for you.

Have you tried Kaivo? Does it behave in a similar way when using a similar amount of CPU? If you try Kaivo 1.9.4 (or demo) and let me know, it might provide a clue.

This thread has become a catch-all for various slow UI issues in one or more plugins, so I changed the thread title to reflect that.

I will get the Kaivo demo and report back. :+1: