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Conference ssag::ask_ssag

Title:	Ask the Storage Architecture Group
Notice:	Check out our web page at http://www-starch.shr.dec.com
Moderator:	SSAG::TERZAN

Created:	Wed Oct 15 1986
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	6756
Total number of notes:	25276

6343.0. "UltraSCSI and FAST10 " by MSE1::PCOTE (Rebuilt NT: 163, Rebuilt VMS:1) Fri Jan 24 1997 14:13


  Will UltraSCSI devices run at optimal speeds (Fast20 speeds)
  in an BA35X storage enclosure ?  Assuming of course I have a
  UltraSCSI controller.

  Can I mix FAST10 devices with UltraSCSI devices ?

  What about existing HSZ products such as a HSZ50. I assume
  since the HSZ50 controller is FAST10 then the Ultra devices
  will run in "fast10 mode".

  Thanks in advance,
  Paul

T.R	Title	User	Personal Name	Date	Lines
6343.1		SSAG::LARY	teach 10,000 stars how not to dance	`Tue Feb 04 1997 11:13`	30
	Will UltraSCSI devices run at optimal speeds (Fast20 speeds) in an BA35X storage enclosure ? Assuming of course I have a UltraSCSI controller. They will run at full speed in a BA356, but you will have to meet the UltraSCSI system electrical requirements for bus length, termination, etc. They are more stringent than the Fast10 requirements, however we will be offering some goodies that actually will make UltraSCSI usable at full speed in many configurations where Fast 10 would not work. I can't say much more in an unrestricted notes conference. Can I mix FAST10 devices with UltraSCSI devices ? In general, yes. A well behaved Fast10 device will not be disturbed by the UltraSCSI devices talking on the bus at UltraSCSI speeds, nor will it screw up the bus electrical environment (by loading it excessively) so the UltraSCSI devices won't work. However, not all Fast10 devices are well-behaved. Thats why we do so much testing. Our UltraSCSI testing to date has shown that all our Fast10 magnetic disks are well behaved; we are looking at tapes and optical stuff now. If we find any old devices that screw up, we will list them as exceptions and recommend you avoid mixing them with UltraSCSI devices running at UltraSCSI speeds. What about existing HSZ products such as a HSZ50. I assume since the HSZ50 controller is FAST10 then the Ultra devices will run in "fast10 mode". Yes, Fast10 and narrow, if you put them in a BA356 with a narrow personality card.
6343.2		MSE1::PCOTE	Rebuilt NT: 163, Rebuilt VMS:1	`Mon Feb 10 1997 15:13`	2
	thanks richie ...
6343.3	Ultra Wide SCSI FAQ	ZPOVC::CSNAQS		`Thu Apr 10 1997 04:18`	8
	Am I correct to say that the Fast Wide Differential Controller will support Ultra Wide SCSI disk but at the speed of 20MB/s ? Vice Visa, the Ultra Wide SCSI Controller will support Ultra Wide SCSI disk a a speed of 40MB/s. Does the Ultra Wide SCSI Controller support Fast Wide Disk and Fast narrow disk ? Thanks
6343.4		OTOOA::LAVIGNE		`Thu Apr 10 1997 16:21`	4
	It depends on your controller. You may want to get out to the Ultra SCSI roll-out training in SHR in early May. Or go out and buy your local storage rep lunch and he will tell you all about what is coming out.