Path: utzoo!utgpu!water!watmath!clyde!att!ucbvax!CORY.BERKELEY.EDU!dillon
From: dillon@CORY.BERKELEY.EDU (Matt Dillon)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga floppies (was: Re: Blitter vs. 80386)
Message-ID: <8808260829.AA08713@cory.Berkeley.EDU>
Date: 26 Aug 88 08:29:10 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 22

:Unix, though, still is no speed demon on searching directories,
:insofar as finding a particular program to run. Directories, at least
:under old AT&T versions, are sequentially organized in no particular
:order -- meaning an O(n) search time, where n is the number of files
:in all those directories.  That's why csh and ksh have hacks in them
:to speed up finding programs (hash tables, etc.), which are just as
:much hacks as the "fastdir" programs on the Amiga.

:
:Of course, Unix DOES have disk caching, while MSDOS doesn't... and
:most Unix systems DO have faster disk drives than MSDOS machines...
:but, all in all, the performance for directory searches should be
:similiar between the two systems.

	Plus the fact that the CSH remembers all the executables in your
search path, and most programs are run from a shell.  All BSD UNIX versions
after 4.1 (i.e. 4.2, 4.3) use very intelligent caching and very fast
access so this isn't a problem.  4.3 additionaly caches directory paths in
the kernel for even faster access.  (namei is cached).  The big thing though
is the CSH.

				-Matt