Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!usc!samsung!spool2.mu.edu!uunet!mcsun!hp4nl!phigate!philica!adrie From: adrie@philica.ica.philips.nl (Adrie Koolen) Newsgroups: comp.os.minix Subject: Re: AmigaMINIX HD driver available! Keywords: Amiga, harddisk Message-ID: <731@philica.ica.philips.nl> Date: 10 Jan 91 15:32:14 GMT References: <8700@star.cs.vu.nl> Reply-To: adrie@beitel.ica.philips.nl (Adrie Koolen) Organization: Philips TDS, Innovation Centre Aachen Lines: 46 In article <8700@star.cs.vu.nl> raymond@cs.vu.nl (Raymond Michiels) writes: >PS: if you're interested in performance figures: > > AMIGA (7MHz A500 + A590 with build-in XT drive): > > through file system (block special device): 73.1 K/sec > (dd if=/dev/hd2 of=/dev/null bs=27k count=128) > > 'direct' (character special device): 138 K/sec > (dd if=/dev/rhd2 of=/dev/null bs=27k count=128) > > 'normal' use: (mounted as a file system): 24.1 K/sec > (cat /user/bin/* >/dev/null ; #almost 2Mb) > > ATARI (8MHz 1040ST + SH205) under the same conditions: > > 39.3 K/sec, 244 K/sec, 19.1 K/sec. > > PC (12 MHz Zenith-AT + unknown drive) under the same conditions: > > 47.0 K/sec, N.A., 38.2 K/sec When I see performance numbers, I immediately want to try how `my' Minix on a standard SparcStation 1 performs: SparcStation 1 (20MHz Sparc + 105MB Quantum ProDrive): 314 K/sec, 494 K/sec, 126 K/sec Honesty makes me note, that my SCSI driver is optimized for reading. Writing would be much slower. Also note that with 314 KB/s, relatively much time is spent in copying: reading blocks in a local buffer in the SCSI driver, copying it to the FS buffer cache, copying it to the dd data space and copying it back to the FS buffer cache. This means that almost 1 MB data per second is copied! The last of the three numbers is the most important one. It indicates much more than only the speed of the disk driver (and the drive itself; the Quantum P105S tops at 1MB/s). Seek speed and CPU speed is important as well. As could be expected the Atari and Amiga are close together with 19 and 24, whereas the 12MHz AT is significantly faster with 38 KB/s. The SparcStation performs much better with 126 KB/s. I assume, that a 25 or 33MHz 386/486 with a fast disk can yield even higher numbers! Adrie Koolen (adrie@ica.philips.nl) Philips Innovation Centre Aachen