Why Byte-Coded Commands Can Be Faster Than C-Coded Commands
Byte-Coded commands are sometimes faster than commands implemented in an external language like C. MS, Tcl Chatroom, 2013-12-31, offered these reasons:
Byte-coded commands access local variables directly, whereas commands implemented in C have to resolve them at runtime.
Dispatch to an external command is slower than dispatch to a byte-coded command
Often, only the most frequently-used code-paths of a command are byte-coded, and corner cases fall back to the C implementation of the command.