[comp.periphs.scsi] favorite SCSI controller chips

kenyee@ksr.com (Ken Yee) (12/29/90)

As a curiosity question, what do people think is the fastest (designable
throughput as opposed to spec claims) SCSI chip out?  Which company will
have the fastest in the next 6 months?

My opinion:
    Adaptec 6250
	- 3 Mbytes/sec Async
	- 5 Mbytes/sec Sync (using only an offset of 8...NCR's 53C90 needs
	  an offset of 16 for this speed).
	- 10 (8 bit bus) or 20 (16 bit bus) buffer DMA transfer.
	- Arbitration and Selection into command phase done in hardware.
    Next 6 months:  Adaptec with SCSI-2 chips (SCSI compatible connectors).

I'll do a post to the net if there is sufficient interest.

   Ken    (kenyee@ksr.com  or  uunet!ksr.com!kenyee)

neese@adaptx1.UUCP (01/04/91)

>/* ---------- "favorite SCSI controller chips" ---------- */
>As a curiosity question, what do people think is the fastest (designable
>throughput as opposed to spec claims) SCSI chip out?  Which company will
>have the fastest in the next 6 months?
>
>My opinion:
>    Adaptec 6250
>	- 3 Mbytes/sec Async
>	- 5 Mbytes/sec Sync (using only an offset of 8...NCR's 53C90 needs
>	  an offset of 16 for this speed).
>	- 10 (8 bit bus) or 20 (16 bit bus) buffer DMA transfer.
>	- Arbitration and Selection into command phase done in hardware.

Actually, if you are design engineer working on an AT bus type implementation
the AIC-6260 is a better choice.  It has the AT bus built in and a much better
software interface than the 6250.  It does everything the 6250 does plus some
more stuff.  It also support FAST SCSI-2.

>    Next 6 months:  Adaptec with SCSI-2 chips (SCSI compatible connectors).

The AIC-6251 chip is out and also support FAST SCSI-2.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
				uunet!cs.utexas.edu!utacfd!
				  {nominil,merch,cpe}!adaptex!neese
				uunet!mlite!adaptex!neese

ts@cup.portal.com (Tim W Smith) (01/05/91)

The NCR 53C710 should be considered in this thread.  Especially if
one considers total time to execute a command, rather than just the
time spent in the data phase.

						Tim Smith