larry@focsys.uucp (Larry Williamson) (09/13/90)
I must write > 1 Gigabyte of data to a tape on a 386 system running Unix 3.2. It may be either an ISA bus (or EISA bus system if a scsi controller is available). I expect to use an Exabyte drive (what else would be faster?), an adaptec 1542 controller (for both tape and disk). What data rate should I expect to be able to maintain for the duration of the write? More importantly, how long would an operator expect to wait before they could remove the tape? -Larry
karl@robot.uucp (Karl-P. Huestegge) (09/24/90)
In <LARRY.90Sep13141156@focsys.uucp> larry@focsys.uucp (Larry Williamson) writes: >I must write > 1 Gigabyte of data to a tape on a 386 system running >Unix 3.2. It may be either an ISA bus (or EISA bus system if a scsi >controller is available). I expect to use an Exabyte drive (what else >would be faster?), an adaptec 1542 controller (for both tape and >disk). >What data rate should I expect to be able to maintain for the duration >of the write? I use an adaptec 1542B with a Tandberg SCSI-Streamer 320/525MB under SCO-Xenix 2.3. The drive comes into streaming mode with 150MB tapes, but not fully with 320MB tapes (it rewinds for a second after 5-7 sec of streaming). In spite of that i get a real world transfer rate of 480 MB/h with the 320MB tapes. - The bottleneck is not the streamer, but the OS. Under DOS it streams and i get a rate of 600MB/h (Adaptec Sytos). So i doubt that an Exabyte will be faster. (If it cannot stream it's even slower.) >More importantly, how long would an operator expect to wait before >they could remove the tape? With my system he would wait 105 minutes, if you changed the cartridge afer 52 min. (Otherwise you might wait longer :-) Karl-Peter -- Karl-Peter Huestegge karl@robot.mbx.sub.org Niedstr. 19 (karl@netmbx.de) 1 Berlin Friedenau ..tmpmbx!einoed!utopia!robot!karl +49 (0)30-851 81 98