Not every access violation in DelphiSpeedUp.dll is a bug in DelphiSpeedUp. They only exist in memory and are limited to the Delphi/BCB/BDS process.
Uninstalling DelphiSpeedUp reverts every change because the optimizations aren’t persistent. They are made in memory keeping all the files on disk unmodified. Important information: All these optimizations do not affect the compiled projects in any way.
It also employs caches when the IDE loads. This is achieved by replacing some often used RTL functions by FastCode function that are optimized for the used CPU and some other faster implementations. It improves the IDE’s startup speed and increases the general speed of the whole IDE.
DelphiSpeedUp is an IDE plugin for Delphi and C++Builder.