neese@adaptx1.UUCP (05/07/91)
>/* ---------- "Re: EISA SCSI controllers?" ---------- */ >piety@hplred.HP.COM (Bob Piety) writes: > >>A very fast SCSI card for teh EISA bus is the ADAPTEC AHA-1740. It >>offers a 1540 ("compatibility") mode for old drivers, as well as the >>fast enhanced mode. > >What is 'very fast'? In what environment? > >Mylex is best EISA-SCSI controller, what I have tested, but it doesn't >fit to the OS/2-wordl, because of missing HPFS (working ones) drivers. > >Adaptec 1740 works allright with OS/2 HPFS, and with SCO Unix, but >the performance is not so good, as with Mylex. I think it is mostly >because of missing HW-cache on-board. Interesting. What hard drive was used? Which mode was the 1740 in? Was tag queuing used? Was the drive a FAST SCSI-2 drive? I don't want to get into vendor bashing here, but I have run the Mylex board against the 1740 and, suffice it to say, my results were quite different. The drive I was using supported FAST SCSI-2 (10MB/sec) and tag queuing. I used the same drive on the Mylex board as well. In a recent BYTE article, they claimed the HP Vectra 486 has the fastest disk subsystem they have ever tested. I looked back over some other issues of BYTE and found the Mylex stuff. Indeed the HP did outperform the Mylex using the 1740. Of course, HP's system also uses a very high performance SCSI disk drive as well. I guess that's my point. SCSI can be made to look any way you want it to. Put a slow SCSI disk on the system and the caching adapter will probably out run the non-caching adapter in some environments. Although I find it hard to believe someone would put a Seagate 296N on a 486/33 EISA system, but I guess stranger things have happened. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese