Adaptec 154x Tuning for SCO Unix

John Maline john at ticipa.ti.com
Thu Jun 28 23:16:12 AEST 1990


A recent thread here has discussed tuning some parameters in the Adaptec
154x driver in 386/ix.  Is there an equivalent set of (administrator
accessible) parameters in SCO Unix?

I've tried enabling synchronous negotiation and increasing the DMA
transfer speed via the on-board jumpers.  Neither showed any significant
change in my simple benchmark (aside from an I/O error when DMA was set
to 8 MB/s).

Background:

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

I interpret these similar results to indicate that SCO's driver
overrides the jumpers in software (as the Adaptec 1542a manual implies
can be done on p 2-14).  This doesn't explain the I/O error at 8MB/s,
though...

System Configuration:
AST 386/33, 10Mb RAM, Adaptec 1542a, Maxtor 4170S, root partn=129397K
SCO Open Desktop (Unix V.3.2.1)

Any help/info would be greatly appreciated.

Regards,

John Maline                    UUCP: john at ticipa@tilde.ti.com
Texas Instruments                                          
PO Box 655012  M/S 3635        TI MSG:  JWMX
Dallas, TX 75265               Voice:   (214) 917-2245



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