maltasr@csusac.ecs.csus.edu (Robert Maltas) (01/16/91)
I was joining together 2 files a week ago and noticed quite a bit of thrashing
on my hard drive. I have a GVP Series II card and 210 meg Quantum ProDrive.
One of the two files I was joining was 6 megs, so I placed this in a RAM:
disk; the other file was 1.5 megs, which resided on my hard drive. The file
which was formed by the JOIN command was directed to the same hard drive
(where the 1.5 meg file resided).
If I had a second hard drive, so that the newly formed file was created
on that hard drive (i.e. no 2 files are on the same device now), would
this get rid of heavy disk thrashing?
Robert Maltas
bobm@csufres.csufresno.edu
maltasr@csus.ecs.edu
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\XX/ Internet: maltasr@csusac.csus.edujesup@cbmvax.commodore.com (Randell Jesup) (01/16/91)
In article <1991Jan15.211044.3827@csusac.csus.edu> maltasr@csusac.ecs.csus.edu (Robert Maltas) writes: >I was joining together 2 files a week ago and noticed quite a bit of thrashing >on my hard drive. I have a GVP Series II card and 210 meg Quantum ProDrive. >One of the two files I was joining was 6 megs, so I placed this in a RAM: >disk; the other file was 1.5 megs, which resided on my hard drive. The file >which was formed by the JOIN command was directed to the same hard drive >(where the 1.5 meg file resided). >If I had a second hard drive, so that the newly formed file was created >on that hard drive (i.e. no 2 files are on the same device now), would >this get rid of heavy disk thrashing? Yes, most of it. Join is usually used on small files, and uses normal buffered input (which has ~200 byte buffers), so it does a lot of single-block reads and writes. On a single drive, this may mean a lot of seeking back and forth. Increasing the number of buffers may help somewhat, but not incredibly. A program that does large reads/writes would be MUCH faster than even the 2-drive solution. -- Randell Jesup, Keeper of AmigaDos, Commodore Engineering. {uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com BIX: rjesup The compiler runs Like a swift-flowing river I wait in silence. (From "The Zen of Programming") ;-)