From owner-freebsd-questions Wed Dec 6 14:38:59 1995 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id OAA28214 for questions-outgoing; Wed, 6 Dec 1995 14:38:59 -0800 (PST) Received: from Apollo.dmacc.cc.ia.us (apollo.dmacc.cc.ia.us [161.210.216.100]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id OAA28191 for ; Wed, 6 Dec 1995 14:38:41 -0800 (PST) Received: from vislab19.dmacc.cc.ia.us (vislab19.dmacc.cc.ia.us [161.210.217.130]) by Apollo.dmacc.cc.ia.us (8.6.9/8.6.9) with ESMTP id QAA22627; Wed, 6 Dec 1995 16:38:37 -0600 Received: by vislab19.dmacc.cc.ia.us (940816.SGI.8.6.9/940406.SGI) id QAA20934; Wed, 6 Dec 1995 16:38:23 -0600 From: "Charles F. Randall" Message-Id: <9512061638.ZM20932@vislab19.dmacc.cc.ia.us> Date: Wed, 6 Dec 1995 16:38:23 -0600 In-Reply-To: julian@TFS.COM (Julian Elischer) "Re: Adaptec 2940W vs Seagate 32550W" (Dec 4, 5:10pm) References: X-Mailer: Z-Mail (3.2.0 26oct94 MediaMail) To: julian@TFS.COM (Julian Elischer) Subject: Re: Adaptec 2940W vs Seagate 32550W Cc: questions@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-questions@freebsd.org Precedence: bulk Julian, Note: I've carbon-copied this to questions@freebsd.org System: Gateway 133MHz Pentium 64 MB RAM Adaptec 2940W SCSI Controller Seagate "Barracuda" 2.1 GB Drive (ST32550W) I've re-partitioned and installed 2.1 on another Barracuda and am seeing similar (poor) filesystem performance (~3 MB/s compared to the ~5 MB/s sequential block read rate I saw on the Seagate Hawk drive). Figuring that I'd messed something up before, I used a "standard" 2047/64/32 geometry and took the default partition sizes. That didn't change performance much (if any). Is there some "optimal" geometry and partition size combination that I could derive from some set of formulas or is this a "black art"? I've appended Seagate's tech sheet for the 'Cuda drive below. I can only note that this drive is listed with a speed of 3600 RPM in the disklabel but it is actually a 7200 RPM drive. Here are the performance numbers I'm seeing with this configuration. For the raw device, flash:~> time dd if=/dev/rsd0 bs=64k of=/dev/null count=1000 1000+0 records in 1000+0 records out 65536000 bytes transferred in 9 secs (7281777 bytes/sec) 0.000u 0.155s 0:09.68 1.5% 63+331k 0+0io 0pf+0w flash:~> time dd if=/dev/rsd0 bs=64k of=/dev/null count=1000 1000+0 records in 1000+0 records out 65536000 bytes transferred in 9 secs (7281777 bytes/sec) 0.010u 0.148s 0:09.50 1.5% 67+301k 0+0io 0pf+0w Using Bonnie on /usr/cuda, -------Sequential Output-------- ---Sequential Input-- --Random-- -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU cuda 128 3217 62.9 3072 13.8 2016 17.3 5067 97.2 5542 23.5 146.3 6.5 The disklabel is, (output of "disklabel -r sd0") # /dev/rsd0c: type: SCSI disk: sd0s1 label: flags: bytes/sector: 512 sectors/track: 32 tracks/cylinder: 64 sectors/cylinder: 2048 cylinders: 2047 sectors/unit: 4194058 rpm: 3600 interleave: 1 trackskew: 0 cylinderskew: 0 headswitch: 0 # milliseconds track-to-track seek: 0 # milliseconds drivedata: 0 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 65536 0 4.2BSD 0 0 0 # (Cyl. 0 - 31) b: 284864 65536 swap # (Cyl. 32 - 171*) c: 4194058 0 unused 0 0 # (Cyl. 0 - 2047*) e: 61440 350400 4.2BSD 0 0 0 # (Cyl. 171*- 201) f: 3782218 411840 4.2BSD 0 0 0 # (Cyl. 201*- 2047*) During boot, I noticed the following: ... ahc0 rev 0 int a irq 9 on pci0:13 ^^^^^^ ahc0: 2940 Wide Channel, SCSI Id=7, aic7870, 16 SCBs ahc0 waiting for scsi devices to settle (ahc0:0:0): "SEAGATE ST32550W 0016" type 0 fixed SCSI 2 sd0(ahc0:0:0): Direct-Access 2047MB (4194058 512 byte sectors) de0 rev 17 int a irq 9 on pci0:14 ^^^^^^ de0: DC21041 [10Mb/s] pass 1.1 Ethernet address 00:00:c0:01:7f:c7 ... Is it normal that the controller and ethernet card would both use IRQ 9? Could this interfere with performance? If I'm bothering you or there's someone else I should be contacting about this, just let me know. Thanks for your help, -Randy http://www.seagate.com/techsuppt/drivespecs/scsi/st32550w.html --- snip --- ST-32550W Barracuda 2LP UNFORMATTED CAPACITY (MB) ________________2541.3 FORMATTED CAPACITY (xx SECTORS) (MB) _____2147.4 AVERAGE SECTORS PER TRACK ________________108 rounded down ACTUATOR TYPE ____________________________ROTARY VOICE COIL TRACKS ___________________________________38,610 CYLINDERS ________________________________3,510 user HEADS ______PHYSICAL______________________11 DISCS (3.5 in) ___________________________6 MEDIA TYPE _______________________________THIN FILM RECORDING METHOD _________________________ZBR RLL (1,7) INTERNAL TRANSFER RATE (mbits/sec)________49.4 to 72.0 EXTERNAL TRANSFER RATE (mbyte/sec) _______5 Async EXTERNAL TRANSFER RATE (mbyte/sec) _______5.0 to 20 Sync SPINDLE SPEED (RPM) ______________________7,200 AVERAGE LATENCY (mSEC) ___________________4.17 BUFFER ___________________________________512 KByte Read Look-Ahead, Adaptive, Multi-Segmented Cache INTERFACE ________________________________SCSI-2 FAST Wide BYTES PER TRACK __________________________64,160 average SECTORS PER DRIVE ________________________ TPI (TRACKS PER INCH) ____________________4,048 BPI (BITS PER INCH) ______________________72,680 AVERAGE ACCESS (ms) (read/write)__________8.0/9.0 Drive level without controller overhead SINGLE TRACK SEEK (ms) ___________________0.6/0.9 MAX FULL SEEK (ms) _______________________17/19 MTBF (power-on hours) ____________________800,000 SHOCK (G's): operating (Read/Write) __________2 nonoperating ____________________50 ACOUSTICS (typ/max dBA) __________________4.7/ POWER REQUIREMENTS: +12V START-UP (amps) _1.26 +12V TYPICAL (amps) __0.88 idle +5V START-UP (amps) __0.91 +5V TYPICAL (amps) ___0.33 idle IDLE (watts) _________ LANDING ZONE (cyl) _______________________AUTO PARK IBM AT DRIVE TYPE ________________________0 or NONE Physical: Height (inches/mm): 1.00/25.4 Width (inches/mm): 4.00/101.6 Depth (inches/mm): 5.75/146.05 Weight (lbs/g): 1.2/545 Already low-level formatted at the factory with 9 spare sectors per cylinder and 1 spare cylinder per unit. ZBR = Zone Bit Recording = Variable sectors per track --- snip --- -- Charles F. Randall E-mail: crandall@dmacc.cc.ia.us UNIX Systems Programmer Voice: (515) 965-7057 FAX: (515) 965-7305