Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!lll-winken!aunro!ersys!bking From: ersys!bking@nro.cs.athabascau.ca (Barry King) Newsgroups: comp.periphs.scsi Subject: Re: Seek-time controller dependent ??? Message-ID: Date: 6 Apr 91 15:04:20 GMT References: <1991Mar28.120818.28142@informatik.uni-erlangen.de> Organization: Edmonton Remote Systems, Edmonton, AB, Canada Lines: 17 It makes sense to me that the speed of the HBA would affect the seeks times. The processor on the HBA must interpret the SCSI command and fire it off to the drive. If the processor is very fast, theSCSI overhead will be reduced and effective seek times will drop and throughput will increase. I used to run my Conner CP3200F with an Adaptec 1540B in a 386/33MHz ISA box. I now use a DPT PM2001/95 (SmartConnex). The difference in seek times between the two HBAs is almost 1 ms in favour of the DPT. The DPT has a full 16 bit path and uses a 10 MHz 68000. The Adaptec uses an 8 bit Intel processor of some sort. Throughput is also several percentage points better using the DPT. I attribute this to the processor speed and maybe the BIOS on the HBA(???). Barry King ersys!bking@nro.cs.athabascau.ca Edmonton Remote Systems: Serving Northern Alberta since 1982