Messages in this thread | | | Date | Sun, 4 Nov 2001 17:31:14 +0100 (CET) | From | Gérard Roudier <> | Subject | Re: Adaptec vs Symbios performance |
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Hi Stephan,
The difference in performance for your CD (slow device) between aic7xxx and sym53c8xx using equi-capable HBAs (notably Ultra-160) cannot be believed a single second to be due to a design flaw in the aic7xxx driver.
Instead of trying to prove Justin wrong with his driver, you should look into your system configuration and/or provide Justin with accurate information and/or do different testings in order to get some clue about the real cause.
You may have triggerred a software/hardware bug somewhere, but I am convinced that it cannot be a driver design bug.
In order to help Justin work on your problem, you should for example report:
- The device configuration you set up in the controller EEPROM/NVRAM. - The kernel boot-up messages. - Your kernel configuration. - Etc...
You might for example have unintentionnaly configured some devices in the HBA set-up for disconnection not to be granted. Such configuration MISTAKE is likely to kill SCSI performances a LOT.
Gérard.
PS: If you are interested in Justin's ability to design software for SCSI, then you may want to have a look into all FreeBSD IO-related stuff owned by Justin.
On Sun, 4 Nov 2001, Stephan von Krawczynski wrote:
> On Sun, 04 Nov 2001 11:10:26 -0700 "Justin T. Gibbs" <gibbs@scsiguy.com> wrote: > > > >On Sat, 03 Nov 2001 22:47:39 -0700 "Justin T. Gibbs" <gibbs@scsiguy.com> > wrote > > Show me where the real problem is, and I'll fix it. I'll add the bottom > > half handler too eventually, but I don't see it as a pressing item. I'm > > much more interested in why you are seeing the behavior you are and exactly > > what, quantitatively, that behavior is. > > Hm, what more specific can I tell you, than: > > Take my box with > > Host: scsi1 Channel: 00 Id: 03 Lun: 00 > Vendor: TEAC Model: CD-ROM CD-532S Rev: 1.0A > Type: CD-ROM ANSI SCSI revision: 02 > Host: scsi0 Channel: 00 Id: 08 Lun: 00 > Vendor: IBM Model: DDYS-T36950N Rev: S96H > Type: Direct-Access ANSI SCSI revision: 03 > > and an aic7xxx driver. Start xcdroast an read a cd image. You get something > between 2968,4 and 3168,2 kB/s throughput measured from xcdroast. > > Now redo this with a Tekram controller (which is sym53c1010) and you get > throughput of 3611,1 to 3620,2 kB/s. > No special stuff or background processes or anything else involved. I wonder > how much simpler a test could be. > Give me values to compare from _your_ setup. > > If you redo this test with nfs-load (copy files from some client to your > test-box acting as nfs-server) you will end up at 1926 - 2631 kB/s throughput > with aic, but 3395 - 3605 kB/s with symbios. > > If you need more on that picture, then redo the last and start _some_ > application in the background during the test (like mozilla). Time how long it > takes until the application is up and running. > If you are really unlucky you have your mail-client open during test and let it > get mails via pop3 in a MH folder (lots of small files). You have a high chance > that your mail-client is unusable until xcdroast is finished with cd reading - > but not with symbios. > > ?? > > Regards, > Stephan
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