woods@most.weird.com (Greg A. Woods) writes:

[I think this was about ide drives, but mutated]
 
> Unfortunately with the NetBSD Adaptec driver (1.3.3 and -current) the
> drives never negotiate any more than 10MHz (with 16-bit) transfer rates,
> even though they claim to be able to go to 80MHz.  Perhaps with a higher
> transfer rate negotiation the 9GB drives would perform
> properly....

Bizarro.  I have no problem with my IBM disks getting 20 MHz 
on an AHA2940UW controller.  On my machine at home, I
use only IBM drives, and "options AHC_TAGENABLE" is a
great performance boost.  (I have a Quantum at work for
the moment and it will lock up when that option is set).

I'm using the PCI-based Adaptec card at the office because of:

Adaptec product 0x7895 (SCSI mass storage, revision 0x04) at pci0 dev 20 functio
n 0 not configured
Adaptec product 0x7895 (SCSI mass storage, revision 0x04) at pci0 dev 20 functio
n 1 not configured

No support for on-motherboard thing.  Oh well. :(

BTW, are you sure the drives will do 80MHz, or is that 80 MB/s
(2 bytes per transfer, 40 MHz clock)?

	Sean.

ahc0 at pci0 dev 15 function 0
ahc0: interrupting at irq 11
ahc0: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
scsibus0 at ahc0 channel 0: 16 targets, 8 luns per target
ahc0: target 0 using 16Bit transfers
ahc0: target 0 synchronous at 20.0MHz, offset = 0x8
sd0 at scsibus0 targ 0 lun 0: <IBM, DDRS-39130D, DC1B> SCSI2 0/direct fixed
sd0: 8715MB, 8387 cyl, 10 head, 212 sec, 512 bytes/sect x 17850000 sectors

and

ahc0 at pci0 dev 9 function 0
ahc0: interrupting at irq 15
ahc0: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
scsibus0 at ahc0 channel 0: 16 targets, 8 luns per target
ahc0: target 1 using 16Bit transfers
ahc0: target 1 synchronous at 20.0MHz, offset = 0x8
ahc0: target 1 Tagged Queuing Device
sd0 at scsibus0 targ 1 lun 0: <IBM, DGHS09U, 0350> SCSI3 0/direct fixed
sd0: 8748MB, 8152 cyl, 10 head, 219 sec, 512 bytes/sect x 17916240 sectors
ahc0: target 2 using 16Bit transfers
ahc0: target 2 synchronous at 20.0MHz, offset = 0x8
ahc0: target 2 Tagged Queuing Device
sd1 at scsibus0 targ 2 lun 0: <IBM, DGHS09U, 0350> SCSI3 0/direct fixed
sd1: 8748MB, 8152 cyl, 10 head, 219 sec, 512 bytes/sect x 17916240 sectors
ahc0: target 6 using 16Bit transfers
ahc0: target 6 synchronous at 20.0MHz, offset = 0x8
ahc0: target 6 Tagged Queuing Device
sd2 at scsibus0 targ 6 lun 0: <IBM, DDRS-39130W, S97B> SCSI2 0/direct fixed
sd2: 8715MB, 8387 cyl, 10 head, 212 sec, 512 bytes/sect x 17850000 sectors