http://www.delphigroups.info/2/7/745746.html
I think you can affect it by following this menu trail...
Tools
Environment Options
Preference
Check Project Desktop
Check Desktop and Symbols
Quote
Code completion has become quite slow under Delphi 7 (ctrl+space
and parameter hints), under Delphi 5 it was slow only for the first
time code completion was invoked, but all subsequent code completions
were instantaneous. On Delphi 7 however, it is just as slow each time
(project and libraries are huge).
Any hint to speeding things back up?
Eric