Adaptec 154x Tuning for SCO Unix

[Piercarlo Grandi]

In article <440 at ticipa.ti.com> john at ticipa.ti.com (John Maline) writes:

   My simple I/O speed test was:
   time dd if=/dev/root of=/dev/null bs=10240

   results:                                 time        user       sys
   asynchronous (sync enb jumper off)       7:32.0       0.9       2:17.1
   synchronous                              7:29.3       1.2       2:09.7
   synchronous, DMA=5.7 MB/s                7:29.3       1.0       2:10.1

But reading from the block device entails such colossal kernel overheads
for cache management, as duly documented in the sys time, that it is
hard to gauge raw IO bandwidth. On the other hand, 130 megs in 450
seconds comes to 200-300 KB sec., which is like Larry Snyder's results.
--
Piercarlo "Peter" Grandi           | ARPA: pcg%cs.aber.ac.uk at nsfnet-relay.ac.uk
Dept of CS, UCW Aberystwyth        | UUCP: ...!mcsun!ukc!aber-cs!pcg
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