FLS Checker plugin

Hi all,

I have built a simpleVST2/3 plugin that counts number of FLS slots available.
Please feel free to try.

BTW this is my 1st post to this forum with this account so it might look very suspicious :slight_smile:
I am sure I had opened an account looong ago but couldn’t retrieve it.

Welcome Takashi!

This is going to be really helpful, I am suspecting some of the reports of plugins failing to load has other reasons.
Thank you very much.

Very impressive, thanks and welcome to the Forum.

Thank you, look forward to using this.


Checking cubase 7.5, 8.5 and 9.5 at launch…
this is what i get…

@Takashi: fantastic - now we can see what’s going on at least! Where can I donate (serious question)? :wink:

Thanks for the effort and sharing! Very useful.

nice work!
For sure outlines the issues we’ve had with Cubase 8.5.

BTW results for some other DAW
Reason 9.5 - 78 slots
FL Studio 114 slots


Very nice work, thank you.

Cubase 9.5.20 - 85 slots
VSThost - 116 slots

Cubase 9.5.20 shows 90 slots for me.

Cubase 9.5.20 -> 93 slots

forgot internet connection on, by disabled 96 slots

That is very handy - thank you.

Many thanks for this, very useful!! I recently posted a long article about the subject on the gearslutz forum, explaining the need for visualization of the remaining FLS slots and also describing a work-around strategy, you can find it on the lower half of this page (almost at the end of the page):


One question, could you also make a 32-bit VST2 version of this plugin? As I described in that article I am using the 32-bit process as an additional resource for FLS slots, and I would like to be able to see the number of slots in that process… thanks in advance!

reason 9.5 - 82 slots
sonar x3e - 107
reaper - 117
live 9 lite - 86

It looks iike 9.5 is a step in the right direction. Now we can visually see it perhaps we should figure out what plugin vendors consume the most FLS and hit them up with people power?

Please follow the link as mentioned in my previous post yesterday, you will find there an extensive FLS test for most of the common plugins as well as a work-round strategy for the FLS limitation.

It’s good to get these numbers out in the open. Steinberg is going in the right direction, but we as users definitely need to push the plugin vendors to reduce their slot usage!! UAD and Arturia are my biggest culprits, on average taking up between 2-4 slots per plugin. Whereas Waves uses only 2 no matter how many plugins you use.

I found a way of gaining a few extra slots as well. Drag and drop the plugin onto the Cb icon on desktop and you I always get extra slots over opening Cubase and then opening the project from the Hub. It seems that on my system the Hub takes 6 slots itself (after opening the hub and I see the free slots go down).


I think you can remove the hub and free up FLS by moving it out of Steinberg/Cubase9.5/Components folder. You can move some other stuff out of there too so long as your not using it

Thanks very much for the tool Takashi!
Also thanks lucas for sharing this valuable info. A must read really.