Try running Process Monitor
process monitor logs 3 things for every compound.
CreateFile
QueryBasicInformationFile
CloseFile
this takes like ... forever... (~30s)
if this is a normal behaviour i need to investigate into the few operations with a result "name not found"
like: C:\Users\3d1-7p64\Autodesk\Softimage_2014_SP1\aaOcean
how come it searches there? this path makes no sense... (no addon or plugin directory. and it's the user folder not the workgroup where i have aaOcean)
there are many others like this:
C:\Users\3d1-7p64\Autodesk\Softimage_2014_SP1\[plugin/compound name]
i definitely shouldn't search for this!
or a "not found" error like this: KLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes\Segoe UI
i cannot classify that...
EDIT: just noticed that i get about 280000 not found errors at SI startup...

mostly
HKCU\Software\Classes\shaderlocation
HKCR\shaderlocation