On Fri, Jul 07, 2000 at 03:15:43PM -0700, Erik E. Fair wrote:
> Question: what happens to the bandwidth of an 8-bit 20 MByte/sec bus 
> when you double its width to 16-bits? It doubles to 40 Mbyte/sec.
> 
> You're actually getting Ultra/Wide SCSI there.
> 
> 	Erik <fair@clock.org>

Thanks for the speedy reply Erik.  I think you may have miss read my
dmesg output or maybe I pasted the wrong lines... but here it goes again:

scsibus2 at ncr1: 16 targets, 8 luns per target
sd0 at scsibus2 targ 0 lun 0: <MICROP, 3387WS, x43h> SCSI2 0/direct fixed
sd0(ncr1:0:0): WIDE SCSI (16 bit) enabled
sd0(ncr1:0:0): 20.0 MB/s (100 ns, offset 15)
sd0(ncr1:0:0): M_DISCONNECT received, but datapointer not saved:
        data=41712200 save=820206b0 goal=820206d4.
sd0: 8296MB, 4811 cyl, 21 head, 168 sec, 512 bytes/sect x 16992188 sectors


To me this would indicate that the bus is wide and the 100ns would indicate
10MHz.  1/10MHz == 100ns right?  Instead of the 100ns I should see a 50ns
or 20MHz right?

So this really IS only 20 megabytes per second (aka fast/wide), I still
have a problem :(


Nick Maniscalco