Newsgroups: comp.os.linux.development.system
Date: 1997/07/09

I wrote a benchmark in order testing Linux disk speed are compare result with other OS especialy NT and QNX.

You can retreive source at:

ftp://ftp.fridu.com/pub/fridu/bench.tgz

General aim

 I want to test disk speed with a maximum of contency, in
order build video multimedia application, in order limitting
I/O board cache size system has to be as stable as possible.
This benchmark intent to first determine disk maximum speed
and then check how big fluxtuation can be when application is
reading disk.

I currentely tested

pPro with IDE: pProc with Adpated Ultra Wide bi pProc with DPT raid0 (2disk array and 32MB cache)

The benchmark provide 3 tests:

read
write
read and write (copy)

Avaliable options are:

block size
synchronization rate (give system constancy)
file size

First result

IDE and PPro a little more than 3MB/s
PPro SCSI Adapted less than 4MB
bi PPro & DPT Raid0 a little more than 7MB

HOW to

First recompile benchmark (should be easy at least on Linux)
Check for raw performances (with no synchro)
Check constancy with a synchro (usualy 16 or 33ms) with
rate from 1MB to your system Limit by increment of 1MB
try to find out your best block size on my system 64KB
was usualy in good value for block size.

Final result

   If you send me your result by mail (phillf@iu-vannes.fr)
I will send a global result on news at the end of August.

Warning

   Take a file big enougth on our University BiPro with 256MB Ram
we notice than Linux is able to read 150MB in less than 1seconde
(impossible except with everything in cache).