kirchner@informatik.uni-kl.de (Reinhard Kirchner) (08/03/90)
From article <WAYNE.90Aug2143750@dsndata.uucp>, by wayne@dsndata.uucp (Wayne Schlitt): > > I have wondered about this for a long time. Are there many drives > with more than one actuators? Why arent there more? > As far as I know the only drives with two HDA ( Head-Disk-assembly ) are large blue ones like 3380, 3390 I don't know. Even on the 3380 the to heads do not overlap, they are two drives on one spindle and one stack of platters. Somewhere I read that this gives more reliability than two drives with two motors etc. Two overlapping indepenant HDAs on one drive may give a lot of trouble to the operating system. We may now have one drive at two controllers and to channels, but then the drive is busy when one controller uses it. With two independant HDA we have totally asynchronous access to the same data! R. Kirchner Univ. Kaiserslautern, Computer Science kirchner@informatik.uni-kl.de
andrew@alice.UUCP (Andrew Hume) (08/04/90)
despite all teh claims about extravagent expense and enourmous difficulty in providing multiple heads, seagate nee imprimis ship a sabre 2HP, a two headed version of the old sabre 1.2GB drive (8in). it has about 20% less capacity, costs about 20% more but runs twice as fast. it seems to me that this is mainstream low-medium cost technology.