Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!cmcl2!rutgers!sunybcs!boulder!hao!oddjob!gargoyle!ihnp4!ihlpe!dpbaudra From: dpbaudra@ihlpe.ATT.COM (Braune) Newsgroups: comp.sys.att Subject: Re: interleave/cluster size on 6300 w/ 3.2 Message-ID: <2119@ihlpe.ATT.COM> Date: Thu, 1-Oct-87 11:05:40 EDT Article-I.D.: ihlpe.2119 Posted: Thu Oct 1 11:05:40 1987 Date-Received: Mon, 5-Oct-87 07:46:15 EDT References: <2310@sphinx.uchicago.edu> <710@neoucom.UUCP> Reply-To: dpbaudra@ihlpe.UUCP (452is-Braune,D.P.) Organization: AT&T Bell Laboratories - Naperville, Illinois Lines: 193 In article <710@neoucom.UUCP> wtm@neoucom.UUCP (Bill Mayhew) writes: > >There doesn't really seem to be a pat answer on what interleave >factor is best. A lot depends on the applications programs as well.... > >In general, I've found that with the WX series (non RLL) >controllers and Seagate 225s, an interleaf factor of 6 seems to >work well with the 6300........... > >For RLL controllers, an interleaf factor of 3 or, perhaps, 4 seems >to do pretty well.......... > >I noticed right away that DOS 3.2 seems slower than 3.1. Remember >that the internal processing is greater for reading a given size..... > >What does irk me is the $$##%@&! clock bug introduced into DOS 3.2. >Each time the system is warmbooted, the dag-gone IBMDOS.COM gets >the T.O.D. from the battery-backed clock. In the process, it sets....... > >Bill > >Bill Mayhew, Electrical Engineering >Division of Basic Medical Sciences >Northeastern Ohio Universities' College of Medicine >Rootstown, OH 44272-9989 USA phone: 216-325-2511 >(wtm@neoucom.UUCP ...!cbsogd!neocom!wtm) I've been meaning to post this info for some time particularly each time I see the question appear. I, too, wanted to know if my St225 and WD WX2 were performing at their optimum. A friend gave me some P/D software that first checked the number of revolutions to read a track and then the data xfer rate. Another pgm actually tried to determine the optimum interleave, trying factors from 1 to 16. At the end of this posting I've included the data I accumulated during the process; it includes stopwatch timing of some common pgm loads from hard disk as well as some of the analysis pgm results. For the ST225/WD WX2 combo, I found 6 to be the best interleave and that has been confirmed other places on the NET. I also have another 6300 with a WD RLL cntrlr and a Miniscribe 3425 that I formatted as a 30 MB drive (I fully recognize what I have done, understand some or all of the potential dangers, and use the machine in a totally non-critical application); there the best interleave was 7 and the optimizer pgm failed to give good results which meant a lot of tedious test-reformat-test cycles. End result as shown is a healthy increase in the speed of disk I/O operation and a noticeable speed of access to pgms such as LOTUS 1-2-3 (admittedly when you start in the subbasement even the 2nd floor looks high). I have since retrieved some good discussions on interleave, low level format, WD BIOS versions, and step rate suggestions from Ed Hopper's BBS in Houston, TX (1-713-782-5474). I also downloaded a pgm called CORETEST which sounds like a common piece of SW for these tasks. I'm sorry I have no before/after results for CORETEST. I will be trying an 18msec step rate on the ST225 as soon as I get some time. Info I retrieved says one needs the WD T.8 BIOS or later to change all the low level format params. I've included the results of reformatting with DOS 3.2 from 3.1; 15.3% space saving. Hopper's BBS has file containing a patch for the BIOS/clock problem. For what its worth, here's my data: TABLE 1 ------- SPINTEST and HOPTIMUM Results for ST225 hdisk(20MB) and WD Cntlr Interleave Read Revs to Data factor Time(sec) Read 1 trk Rate(B/sec) =========== ========== ========== =========== 1 14 2 15 3 16 20 21000 <=== Org lo lvl frmt 4 16 5 13 16 32640 6 6 6 87040 4.14 x Data rate 7 7 7 74596 8 9 10 10 52224 11 12 12 43520 13 14 15 16 16 32640 TABLE 2 ------- Load time tests for ST225 hdisk(20MB) and WD Cntlr for IL=3 and IL=6 Interleave=3 Interleave=6 SPINTEST=20 SPINTEST=6 Date rate=21000 Date rate=87040 Load Load Percent Program Time(sec) Time(sec) Decrease =========== ========== =========== ========= L123 12.5 7.8 37.6% dBASE III+ 10.0 6.1 39.0% WordPerfect 15.0 7.2 52.0% Multiplan 7.3 3.7 49.3% CHKDSK(exec time) 13.6 * 16.6 @ 4.2%Increase PC/VI 3.3 GEM 11.3 Spintest(exec time) 28.5 L123 file1(75490B) 11.7 L123 file2(122269B) 19.1 Size(Bytes) Exec rate ---------- ---------- * 16670720 1225788.2 Bytes/sec @ 21204992 1277409.1 Bytes/sec TABLE 3 ------- Results of ST-225 hdisk(20MB) Reformat MS-DOS 3.1 to 3.2 MS-DOS 3.1 MS-DOS 3.2 Virtual Single C/D drives C drive Space Percent (4096/clus) (2048/clus) Gain Gain ========== ========== =========== ========= Avail bytes C 3141632 9078784 Avail bytes D 4730880 ---------- ---------- ----------- --------- Total bytes 7872512 9078784 1206272 15.3% TABLE 4 ------- SPINTEST and HOPTIMUM Results for Miniscribe 3425 hdisk(30MB) and WD RLL Cntlr Interleave Read Revs to Data factor Time(sec) Read 1 trk Rate(B/sec) ================= ========= ========= ========= 1 14 2 24 3 25 4 15 19 27472 <=== Org lo lvl frmt 5 16 6 14 17 30719 1.12 x Data rate 7 15 5 104448 3.80 x Data rate 8 6 87040 3.17 x Data rate 9 6 87040 3.17 x Data rate 10 6 87040 3.17 x Data rate 11 12 8 65280 2.38 x Data rate 13 14 15 16 10 52224 1.90 x Data rate TABLE 5 ------- Load time tests for Miniscribe 3425 hdisk(30MB) and WD RLL Cntlr for IL=3 and IL=6 Interleave=3 Interleave=7 SPINTEST=19 SPINTEST=5 Date rate=27472 Date rate=104448 Load Load Percent Program Time(sec) Time(sec) Decrease ================= ========= ========= =============== L123 11.5 6.7 41.7% dBASE III+ 9.5 5.5 42.1% WordPerfect 13.2 5.8 56.1% Multiplan 6.8 3.2 52.9% CHKDSK(exec time) 16.2 * 14.4 @ 11.1% PC/VI 5.3 2.9 45.3% GEM 15.2 9.9 34.9% Spintest(exec time) 70.8 21.5 69.6% L123 file1(75490B) 11.2 11.2 0.0% L123 file2(122269B) 18.4 18.4 0.0% Size(Bytes)Exec rate --------- --------- * 32428032 2001730. Bytes/sec @ 32428032 2251946. Bytes/sec Dave Braune AT&T Naperville, IL 60566 ihnp4!ihlpe!dpbaudra