trw@gec-rl-hrc.co.uk (Trevor Wright Marconi Baddow) (01/14/87)
Has anyone got a review of reecommended disc drives for VAX under VMS which provide between 5 and 20Mbyte/sec performance or can u suggest any. Trevor Wright GEC Research yc23%a.gec-mrc.co.uk@ucl-cs
cetron@utah-cs.UUCP (01/18/87)
In article <84@gec-rl-hrc.co.uk> trw@gec-rl-hrc.co.uk (Trevor Wright Marconi Baddow) writes: >Has anyone got a review of reecommended disc drives for VAX under VMS >which provide between 5 and 20Mbyte/sec performance or can u suggest >any. WHY???? I recall that the max bandwith of a Qbus is about 4Mbyte/sec in block mode DMA, the Unibus is down around 2.2 Mbyte/sec, the massbuss was only about 4 Mbyte/sec, and the even the great glorious (-: BI bus is about 13 Mbytes/sec and none of dec's controllers are near that fast...
tihor@acf4.UUCP (Stephen Tihor) (01/18/87)
If you really need 5 to 20 megs per second you should look at some of the Attached systems vendors. Aptec has the best rep among my friends in aviation simulations but there are a couple of other companies trying to play in the same sandbox.
mangler@cit-vax.UUCP (01/19/87)
In article <4179@utah-cs.UUCP>, cetron@utah-cs.UUCP (Edward J Cetron) writes: > WHY???? I recall that the max bandwith of a Qbus is about 4Mbyte/sec > in block mode DMA, the Unibus is down around 2.2 Mbyte/sec, the massbuss was > only about 4 Mbyte/sec, and the even the great glorious (-: BI bus is about > 13 Mbytes/sec and none of dec's controllers are near that fast... Unibuses and Massbuses are only half that fast. For that matter, the VAX-750 and VAX-780 memory controllers will only do about 5 megabytes/second, for all the busses (and the CPU) put together. Perhaps the original poster meant mega-bits, not mega-bytes? There are many good SMD disks with transfer rates from 8 to 20 megabits per second. Don Speck speck@vlsi.caltech.edu {seismo,rutgers,ames}!cit-vax!speck