My bad. I assumed the posted verbal description indicating "all heads were positioned on the same cylinder" was accurate without looking at the article and picture.
Clearly from the picture the Seagate really is like the 3380/3390 solution. Two completely independent actuators giving the appearance of two drives in one unit with a shared drive shaft and motor. The doubling of throughput is ONLY because you have two drives that can be accessing or preparing to access totally independent data at the same time, not because of any faster access to a block of data or multiple blocks of data on a single track of one of those devices. Dang! My interpretation would have been a much more intriguing device. Joel C Ewing On 12/20/2017 09:05 AM, Joel C. Ewing wrote: > No, not the same. > > >From the description of the physical characteristics of the 3380 & 3390, > it was clear that each actuator accessed independent platter surfaces. > The R/W heads on different actuators did not access the same physical > surface much less the same physical track. > > The 3380 & 3390 hard drive modules each contained two functionally > independent hard drives within a single module. Putting platters for > both in one module housing reduced costs and size by allowing platters > for two drives to have a shared drive shaft, shared bearings, and a > shared drive motor. > > The Seagate design description clearly indicates two R/W heads > accessing the same physical track. That sounds like they can at a > minimum be used to cut rotational latency time in half, and maybe (not > clear) even read or write different parts of the same track at the same > time with the potential for doing a full-track transfer in only 1/2 > revolution of the disk. If both are true, they have effectively doubled > the peak transfer rate of the drive and cut the latency time in half > without having to increase either the density or rotational speed of the > device. > Joel C Ewing > > On 12/20/2017 07:31 AM, Vernooij, Kees (ITOPT1) - KLM wrote: ... -- Joel C. Ewing, Bentonville, AR [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
