FLS Checker plugin

Thanks, this plugin is very useful.
There are 3 approaches to fixing this issue:

  1. Plugin vendors use dynamic linking and include the appropriate redist in their installers.
  2. Cubase uses multiple processes to host plugins.
  3. MS provides a workaround.
  4. We all switch to Macs.

Even if every plugin vendor used dynamic linking and Cubase used no slots, we’re still stuck with a limit.
Theoretically 128, but most likely around 64 to 100.
I’m getting tired of throwing high end hardware at an OS issue, perhaps option 4 might be the best approach.

Slate Virtual Mix rack eats 36 slots.
can someone confirm same amount ?

I tried latest version ( and it showed me -2 slots for vst2 and vst3

Many thanks for the FLS Tool Takashi!

I’m finding just two slots for VMR vst2/3 also with the latest build.

This is kicking up some rather interesting results actually… The new Arturia preamps are rather hungry too with 8 for The 1973 and 6 for both the TridA and V76 respectively… Analogue Lab3 uses up a WHOPPING 45!!! think i feel a post coming on in the Arturia forum… :wink:

Ozone8 Maximiser uses 8 for vst2/3 which is also pretty hefty!

I think the Analog Lab plugins versions 2 and 3 instantiate every single plugin instrument in the collection immediately when started, whereas the version 1 instantiates the instruments as they are required by the presets (and they’re not released). That’s why they take up so many slots.

Arturia definitely need a (polite but firm) hauling over the coals for being so greedy :open_mouth:


Yes GargoyleStudio it would seem you’re correct re AL & AL3…
Posted on the Arturia forum and got a fairly speedy and gracious reply from Ben… https://forum.arturia.com/index.php?topic=92788.new;topicseen#new if anyone else wants to contribute there too.

Some of the results i’ve been finding are quite surprising… Spectrasonics Trilian only uses ONE FLS slot which was unexpected as it’s a bit of a beast!
BFD3 only uses 2 and again it’s a bit of a beast…

Thanks for that @matjones, very interesting!! I’ll be hoping that they can do something to help. I couldn’t seem to log into the forum, is it different to the Arturia account login?? It doesn’t seem obvious, there’s no info…


FWIW, Ben (I think he leads the beta test group) is the guy who handles Arturias bugs. I had many problems with Arturia “support” until he got involved, and within weeks they fixed a glaring sustain bug with the Prophet V. He is very active, hands on, and will work with you. Just communicate and don’t drop the ball…

Question, so each of my hardware synths plugged in via usb would be using extra slots?

Not necessarily, but if they have integration (usually a dll in the Components or Shared Components folder of Cubase), yes they will.
The UR interfaces also use some slots.

This is great, thank you Takashi!

Ok then, thanks… I only really use a plugin editor for my virus or novation, so they would just use normal slots like other plugins. I have a motif now too though so may use the plugin for that also. We’ll see. Generally I use stand alone editors for my HW synths, or the ipad.

I just hope there is some workaround some day, like cubase opening plugins in a new process once the limit is reached…

(basically, say, cubase could be designed to let the FLS slots max out, with a permanent slot counter shown somewhere in the info line, then when the limit is reached, all plugins from then on could open in a separate process, until the limit is reached again, and so on).

The whole reason I want such a powerful machine is cause i use a LOT of plugins and high track projects… I know I will hit this FLS problem very very quickly if i switch to windows… That’s my main turn off at the moment… well, that and forced windows 10 updates.

fls checker is godsend. At least I know why my cubase projects began to behave weird and I know what to do about it…

Interesting i only had this problem in 8/8.5 and that seems to show why

CP 9.5.40 no project, windows 7 pro, 99 free.
A 40 track project with Cakewalk Dimension Pro, Toontrack SuperiorDrummer2 and the rest Waves stuff - 96 free.
Expected to loose some more.

And thanks for the plugin, really good to get a grip where I am at. :slight_smile:

Analog Lab by Arturia - eats 40 slots!
can somene confirm ?

Anything by Arturia was over 30 slots.
Can´t remember exactly, but yes, mine was around 36-40 slots

Btw, UR44 eats 9 slots

Great news for Windows users…

HAPPY Healthy New Year all! :sunglasses:

Hi All

If any of you test the new Insider build on your non-critical PCs, please feel free to contact me directly with results (or post them here, of course)

pete dot brown at microsoft dot com