Date: Sun, 13 Aug 2000 20:56:41 +0200 (CEST) From: =?ISO-8859-1?Q?G=E9rard_Roudier?= <groudier@club-internet.fr> To: Martin Heller <mheller@mheller.org> Cc: bellefso@execpc.com, freebsd-scsi@FreeBSD.ORG Subject: RE: Tekram DC390U3W Message-ID: <Pine.LNX.4.10.10008132022520.858-100000@linux.local> In-Reply-To: <Pine.A41.4.21.0008032329350.410948-100000@aixd1.rhrk.uni-kl.de>
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Hello Martin, This mail is the only one I received about the 'Tekram DC390U3W' subject. You may want to send me the articles about this topic that missed my mailbox. :) On Thu, 3 Aug 2000, Martin Heller wrote: > Hello Brian, I am not Brian. :) I just want to help if I can. > I see this behaviour with my UW drive, too. Crazy thing is, my DAT-tape > get's 5 MB/s ?? If you mean that this was not the value initially configured in the NVRAM, then the following my have happen: You must have in mind that Domain Validation is part of the Ultra-160 SCSI specifications and that the BIOS delivered with the DC390U3* does perform some integrity checking and therefore may decide to lower the data rate of a device until no error is encountered. I heared that the data rate is divided by two each time an integrity problem is detected. Once Integrity Checking is done, the NVRAM may well get updated with the resulted assumed *best* data rate for each device. You may check if the device data rate in the NVRAM has been modified by BIOS and let me know. The driver has no reason not to trust the NVRAM since it reflects some good compromise between user's wishes and actual hardware capabilities, at least as long as we haven't Domain Validation/Integrity Checking available from the kernel (CAM + SIMs). > I'll test it tomorrow with a U160 disk. Did you get the results you expected ? > The list freebsd-scsi is perhaps more appropriate. Indeed it is, IMO. Gerard. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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