Q Light Controller+

Okay, I've checked several things. On a more powerful PC, 4.14.1-2 doesn't crash.
I opened the Task Manager and monitored the RAM. When loading the project, the committed RAM increases to over 28GB. Then my weaker PC crashes.

When I load the same project file with 4.12.7, almost nothing happens to the committed RAM.

4.14.1-2 seems to be overloading the committed RAM!

Why does 4.14.1-2 require so much committed RAM?

DJKilli wrote: ↑Thu Apr 03, 2025 7:37 am the allocated RAM increases to over 28GB

This can't be right (!)

When QLC+ starts, it needs 36,5Mb on my machine.
Running Proj1: 1253Mb
Proj2: 1939Mb

Both projects can be opened. (To fully test I'd need all your custom fixtures.)

One observation: Your loopback structure. I've always reserved one universe for loopback IN & OUT.
In your project: Loopback1 has its input in universe 1 and its output in universe 3...
I assume that your universe 1 is also the output to light world, and hence, loopback directly influences the output ... I'm not sure this is wanted?

This can't be right (!)

When QLC+ starts, it needs 36,5Mb on my machine.
Running Proj1: 1253Mb
Proj2: 1939Mb

Sorry, I meant the committed RAM!

Attached are two images from my task manager on the more powerful PC.

The committed RAM is marked in red in each case.

Opened Project Two once under 4.12.7 and once under 4.14.1-2.

You can clearly see how the value is increasing under 4.14.1-2. Not much happens under 4.12.7.

At 20GB committed RAM QLC+ crashes on my weaker PC.

(To fully test I'd need all your custom fixtures.)

Here are the fixtures and ModifiersTemplates:

And the profile:

One observation: Your loopback structure. I've always reserved one universe for loopback IN & OUT.
In your project: Loopback1 has its input in universe 1 and its output in universe 3...
I assume that your universe 1 is also the output to light world, and hence, loopback directly influences the output ... I'm not sure this is wanted?

When I started working with loopback, I simply copied .qxw files from the forum where loopbacks were created.

Yes, Universe 1 is my output to the lights.
I thought that was the right thing to do.
Can I make it even better?

Is it intentional that the new QLC+ version requires significantly more RAM, or at least more committed RAM?


This isn't the case with older versions of QLC+. Or is it something wrong with my project file?

DJKilli wrote: ↑Thu Apr 03, 2025 10:16 am

This can't be right (!)

When QLC+ starts, it needs 36,5Mb on my machine.
Running Proj1: 1253Mb
Proj2: 1939Mb

Sorry, I meant the committed RAM!

Attached are two images from my task manager on the more powerful PC.

The committed RAM is marked in red in each case.

Opened Project Two once under 4.12.7 and once under 4.14.1-2.

You can clearly see how the value is increasing under 4.14.1-2. Not much happens under 4.12.7.

At 20GB committed RAM QLC+ crashes on my weaker PC.

Windows 10 x64, QLC+ 4.14.1-2

I did some brute force testing and found that if I removed all the RGBMatrix', saved the project, shutdown QLC+, opened QLC+ and loaded the project without the RGBMatrix', "Committed" remains at a normal level. Reloading the original project pushes "Committed" to about 2.5 times the normal allocation.

I did some brute force testing and found that if I removed all the RGBMatrix', saved the project, shutdown QLC+, opened QLC+ and loaded the project without the RGBMatrix', "Committed" remains at a normal level. Reloading the original project pushes "Committed" to about 2.5 times the normal allocation.

This isn't the case with version 4.12.7.

For me, that means not updating QLC+ or deleting lot of RGB matrix. That can't be what the developers intended, can it?

Guys, let me clarify this once and for all.
You all know QLC+ depends on the Qt libraries.
RGB Matrix scripts (a subset of JavaScript) were processed by a Qt library named QtScript.
The Qt company (not me) decided to mark that library as deprecated and eventually removed it in Qt6.
Now, the world goes on, and I am forced to advance QLC+ to more recent versions of Qt, so with the switch to Qt6 (ATM Windows and macOS Apple Silicon builds) the RGB Matrix engine has changed, with a lot of related painful issues and limitations.
So I guess what you're seeing is a consequence of this little story. Unfortuntely not everything is under my control.

And I'm not even talking about QLC+ 5. The whole 3D engine is under discussion now. It's really frustrating. Believe me.

Okay, so that means newer QLC+ versions are only available with a more powerful PC.
My light notebook isn't bad either: an I5 and 8GB of RAM.
So I'll stick with version 4.12.7 for now.

High RAM usage related to RGB scripts is fixed now: https://github.com/mcallegari/qlcplus/pull/1742

You could try windows build yourself: log into github, then go to https://github.com/mcallegari/qlcplus/a ... 18?pr=1742 and expand "Store executable artifact", there you will find a link to the installer.