News that will possibly only affect a small number of users, but ultimately one that will make their composing life better. The FLS limit in Windows has become more and more apparent in recent years as computer performance has improved and the total number of plugins found within any given project has scaled too.

The FLS slot limit (Fiber Local Storage) has always been in place and places a limit on the total number of unique plugins that can run on a system. Multiple copies of the same plugin can share code and run efficently, so the previous limit of 128 plugs was percieved to be high enough for the average user.

The problem we’ve seen over the years is that some plugs don’t efficiently use their resources and can sometimes use up multiple slots per plugin. Some reports have shown that some software can eat up to 7 or 8 slots per unique plugin, so it should be apparent that for users working with large templates and intensive projects that the ceiling was ever looming.

Todays insiders announcement sees a new FLS limit being included in the download and should public testing prove positive we would expect to see this rolled out to everyone later in the year.

The new limits increase the headroom limit to well over 4000 slots, so this new limit should keep even the most demanding user going for a good few years to come!

The official announcement can be found here: https://blogs.windows.com/windowsexperience/2019/01/09/announcing-windows-10-insider-preview-build-18312/

FLS Slot Limit Increase

As PCs get more powerful, musicians have created increasingly complex projects with more tracks, more instruments, and deeper effects chains. As a result, some of those musicians were running up against a FLS (Fiber Local Storage) slot allocation ceiling that prevented them from loading into their DAWs (Digital Audio Workstations) as many unique plugins as they’d like. This build greatly raises that per-process FLS slot allocation ceiling, allowing loading potentially thousands of unique plugins. Beyond musicians, this change will positively impact any application that dynamically loads hundreds or thousands of unique DLLs that have statically-linked Visual C++ runtimes, or otherwise allocate FLS slots.