I will have to create a multi-threading project soon I have seen experiments ( delphitools.info/2011/10/13/memory-manager-investigations ) showing that the default Delphi me
FastMM deals with multi-threading just fine. It is the default memory manager for Delphi 2006 and up.
If you are using an older version of Delphi (Delphi 5 and up), you can still use FastMM. It's available on SourceForge.