Date: Tue, 28 Sep 1999 18:18:19 +0200 (MET DST) From: Gerard Roudier <groudier@club-internet.fr> To: Kevin Street <street@iname.com> Cc: "Kenneth D. Merry" <ken@kdm.org>, scsi@FreeBSD.ORG Subject: Re: sym driver 0.3.0 Message-ID: <Pine.LNX.3.95.990928181444.476A-100000@localhost> In-Reply-To: <874sgfog96.fsf@mired.eh.local>
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I suggest you to configure the same number of tags for the sym and the ncr using camcontrol after boot, then to redo your testings and post results.= =20 You can be sure I will comment them. G=E9rard. On 27 Sep 1999, Kevin Street wrote: > "Kenneth D. Merry" <ken@kdm.org> writes: > > Gerard Roudier wrote... > > > You test is not serious. If you only can provide 1.5MB/second through= put > > > for a benchmark of SCSI driver, please go away or make comparison wit= h an > > > AHA 1542. I consider your posting to be a bad joke and hope that it i= s not > > > intentionnaly just bad taste.=20 >=20 > This original hasn't made it to me yet so I don't have all the > context. If this comment by Gerard was aimed at me, then my response > is: I'm assuming that you intended the sym driver to be used for real > applications on real machines. If its only purpose is to run > benchmarks, then let me know that and I will go away. >=20 > > I think what you may want to do is ask Kevin to give you some compariso= ns > > of iostat output from dumps with the ncr driver and dumps with the sym > > driver, ... >=20 > I've done a few more tests. I tried to see the effect that the > slow Syquest drive is having. When I dump to an IDE drive then > the sym driver is faster than the ncr by 15-20%. But when I dump > to the Syquest, then the interference slows down the sym driver more > than the ncr. Here's what I got from 8 test runs of dump. >=20 > dump from da1 to ad0 (IBM SCSI to WD IDE) > =09time=09KB/sec > ncr=09246=091764 > ncr=09250=091736 > sym=09211=092056 > sym=09209=092076 >=20 > dump from da1 to da0 (IBM SCSI to Syjet SCSI) > =09time=09KB/sec > ncr=09275=091578 > ncr=09277=091566=09 > sym=09335=091295 > sym=09336=091291 >=20 > Looking at iostat shows dump pushing 64KB blocks at the Syquest > which is almost keeping up. It gets behind occasionally and > the da1 transfers stop until da0 catches up. With the ncr > driver it looks like this: >=20 > tty da0 da1 cpu > tin tout KB/t tps MB/s KB/t tps MB/s us ni sy in id >=20 > 0 30 64.00 24 1.49 4.75 265 1.23 1 0 5 2 92 > 0 30 64.00 25 1.55 4.71 219 1.01 1 0 2 1 97 > 0 30 64.00 23 1.42 0.00 0 0.00 0 0 0 0100 > 0 30 64.00 25 1.55 0.00 0 0.00 0 0 0 0 99 > 0 30 53.92 25 1.30 3.56 275 0.96 1 0 6 1 92 > 0 30 64.00 25 1.55 3.60 564 1.98 0 0 15 2 83 >=20 > On the sym driver, the pauses from da1 are more frequent and > longer. On the Syquest at da0, there's something strange > going on. The transaction rate on da0 drops way off while it's=20 > trying to catch up, which means that da1 is forced to wait > longer before it can start blasting data at it again. >=20 > tty da0 da1 cpu > tin tout KB/t tps MB/s KB/t tps MB/s us ni sy in id >=20 > 0 30 64.00 22 1.36 2.91 397 1.13 0 0 21 18 60 > 0 30 64.00 21 1.30 3.41 292 0.97 1 0 14 21 64 > 0 30 64.00 20 1.24 3.75 82 0.30 0 0 5 21 74 > 0 30 64.00 21 1.30 0.00 0 0.00 0 0 0 27 72 > 0 30 64.00 21 1.30 0.00 0 0.00 0 0 0 26 73 > 0 30 64.00 19 1.18 0.00 0 0.00 0 0 0 24 75 > 0 89 64.00 17 1.05 0.00 0 0.00 2 0 0 17 81 > 0 30 64.00 15 0.93 0.00 0 0.00 1 0 0 14 85 > 0 30 64.00 8 0.50 0.00 0 0.00 0 0 0 8 92 > 0 30 64.00 8 0.50 0.00 0 0.00 0 0 0 1 99 > 0 30 55.27 22 1.18 3.69 702 2.53 2 0 11 6 82 > 0 30 64.00 22 1.36 3.78 670 2.47 1 0 21 16 62 > 0 30 64.00 23 1.42 3.19 478 1.49 1 0 21 17 61 > 0 30 64.00 20 1.24 0.00 0 0.00 0 0 0 22 77 > 0 30 64.00 17 1.05 0.00 0 0.00 1 0 0 16 83 > 0 30 64.00 8 0.50 0.00 0 0.00 0 0 0 9 91 > 0 30 64.00 4 0.25 0.00 0 0.00 0 0 0 4 96 > 0 30 48.95 21 0.99 3.43 520 1.74 2 0 8 2 88 >=20 > So this would appear to be the cause of the slower dumps. > Perhaps this is error recovery activity on da0? Whatever > it is, the sym driver isn't handling it as gracefully as > the ncr. >=20 > --=20 > Kevin Street > street@iname.com >=20 >=20 > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-scsi" in the body of the message=20 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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