eho@reason.Princeton.EDU (Eric Ho) (04/05/89)
Does anyone out there has used the old Quantum 42MB disks on the 1108's or the 8000 fileservers ? I want to know how fast they're compared with the 380 removable trident disk packs using the same CPU (i.e. the 8000's) with the same amount of RAM. Any pointers will be much appreciated. Eric Ho Princeton Cognitive Science Lab., Princeton University email = eho@phoenix.princeton.edu voice = 609-987-2987 -- regards. -eric-
"Bradley_S._Burns.mvenvos"@XEROX.COM (04/08/89)
Eric, I'll attempt to answer your question by providing some of the specs. at hand. Trident T-300 19 data and 1 servo heads 815 cylinders capacity 300 MB Seek time 7.5 ms tract to tract. Average seek time 30 ms maximum seek (815 cyls.) 55 ms Data transfer rate 806 K Bytes/Sec. AMS - 315 Tracks per cylinder 19 No. of cylinders 823 capacity 315.2 MB (Xerox does not use the additional capacity on this drive for compatibility reasons.) Seek time, single tract 5ms (max) Average positioning time 25ms (avg) Max. positioning time 50 ms Data transfer rate 1209 K Bytes/sec. Quantum 2040/2080 (I didn't have the spec. sheet in this drive, but I do on the HSIO controller.) Transfer rate 892.5 K Bytes/Sec. Since the Quantum drives use stepper motors to move the heads I would suspect that the seek times would be at least twice as much as a liner positioner plus 10ms head settling time before a read/write can take place. Not knowing what you're up to, all I can say is, that the two class of drives use different controllers and microcode to drive them. I hope this is of some help. Brad Burns Envos Corp.