Xref: utzoo comp.unix.xenix:12643 comp.unix.i386:7485 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!agate!darkstar!gorn!comix!jeffl From: jeffl@comix.UUCP (Jeff Liebermann) Newsgroups: scruz.general,comp.unix.xenix,comp.unix.i386 Subject: Hard Disk dd benchmarking Keywords: benchmark dd Message-ID: <65@comix.UUCP> Date: 3 Aug 90 04:18:51 GMT Sender: uucp administration Followup-To: poster Organization: COmmittee to Maintain Independent Xenix Lines: 75 I was trying to get some perfomance figures of various OS/machine/drive combinations and discovered some erratic results. The original testing was to determine how detrimental sector translation was to drive performance. A simple dd from the raw device should yield a good approximation of the sequential read performance without involving the kernel buffering (NBUF). The blocked read performance was thrown in just for entertainment value (leaving 100k-600kBytes in buffers). The results were wildly distributed. Question: 1. Is the test valid? 2. Why the 50:1 (best/worst) variation in speed? 3. Am I doing something wrong? Hard Disk Benchmarks. J. Liebermann Thu Aug 2 19:25:55 PDT 1990 =========================================================================== Copies exactly 10Mbytes to /dev/null. Must be root to read /dev/root. block: time dd if=/dev/root of=/dev/null bs=64k count=160 raw: time dd if=/dev/rroot of=/dev/null bs=64k count=160 =========================================================================== Size of root partition-\ /---------------------- Controller Cache Size --------\ | | /-------------- Flavour RAM -----------\ | | | | /------ Drive CPU/CLOCK --\ | | | | | | OS Version --\ | | | | | | | | comix 386/25 4Mb 0k 125Mb ACB1542A SCSI Maxtor 4380S Unix 3.2.0 block real=34.4 sys=12.7 KBytes/sec=344 raw real=56.0 sys=6.4 KBytes/sec=178 adcom 386/25 4Mb 0k 80Mb DTC6280A ESDI Maxtor 4380E Xenix 2.3.1 block real=181 sys=6.8 KBytes/sec=55 raw real=97 sys=3.5 KBytes/sec=103 bucci 386/25 4Mb 0k 65Mb WD1006 1:1 MFM MinScr 3085 Xenix 2.3.1 block real=180 sys=6.4 KBytes/sec=55 raw real=105 sys=3.8 KBytes/sec=95 aton 386/25 12Mb 16k 100Mb ACB1542A SCSI MinScr 9380S Unix 3.2.0 (1) block real=32.6 sys=8.0 KBytes/sec=306 raw real=53.8 sys=3.8 KBytes/sec=187 orion 386/25 8Mb 128k 90Mb WD1007A ESDI Wren V 380mb Xenix 2.3.2 block real=27.7 sys=5.1 KBytes/sec=361 raw real=34.6 sys=2.4 KBytes/sec=289 redwood 386/25 5Mb 64k 35Mb WD1006 1:1 MFM MinScr 3085 Xenix 2.3.3 block real=27.0 sys=5.6 KBytes/sec=370 raw real=25.6 sys=2.6 KBytes/sec=390 redwood 386/20 4Mb 0k 50Mb Ultrastore ESDI MinScr 3180E Xenix 2.3.3 (2) block real=18.4 sys=13.9 KBytes/sec=543 raw real=17.0 sys=3.9 KBytes/sec=588 srccom 386/25 8Mb 64k 200Mb ACB1422B-15ESDI MinScr 9780 Xenix 2.3.2 (3) block real=81 sys=8.4 KBytes/sec=123 raw real=34.6 sys=2.5 KBytes/sec=289 dsch01 386/20 4Mb 0k 80Mb Ultrastore ESDI MiniScr 9380E Xenix 2.3.2 block real=17.0 sys=13.4 KBytes/sec=588 raw real=16.0 sys=3.3 KBytes/sec=625 grumbly 386/20 8Mb 0k 62Mb WD1006 1:1 MFM MicroSci HH1090 Unix 3.2.1 block real=24.9 sys=9.4 KBytes/sec=402 raw real=24.3 sys=1.4 KBytes/sec=412 vdx 386/25 8mb 0k ?Mb WD1007A ESDI Maxtor 4380E & CDC Wren V block real=18.4 sys=17.5 KBytes/sec=550 ISC 2.2 raw real=14.2 sys=7.0 KBytes/sec=704 (2nd controller) ACB1542B CDC 94171-344 & ST4702N block real=14.7 sys=14.2 KBytes/sec=680 raw real=11.0 sys=0.7 KBytes/sec=910 (1) Using Storage Dimension's SCSI driver. (2) Ultrastor has 32K on board cache. (3) Lookahead disabled on controller. (4) Dos partition on aton only. Others are all Unix or Xenix. (5) vdx has 2 controllers and 4 drives. -- # Jeff Liebermann Box 272 1540 Jackson Ave Ben Lomond CA 95005 # (408)336-2558 voice (408)429-0483 digital pager CIS:73557,2074 # PC REPAIR & RF DESIGN. uunet!comix!jeffl pyramid!vdx!comix!jeffl # universe!milky_way!solar_system!earth!na!us!uunet!comix!jeffl