jonm@syma.sussex.ac.uk (Jonathan Meyer) (09/04/90)
talvola@danube.Berkeley.EDU (Erik Talvola) writes: > I will shortly be purchasing a new hard drive, probably the Conner 200 meg > hard drive, which people have given me good reviews about. It is available > in either IDE or SCSI, and I was wondering about the advantages of each. > I know the IDE is supposed to be faster under DOS, but then again, the SCSI > can have a tape drive hooked up later possibly, and may have better Unix > performance. I am not even sure if IDE drives are generally supported under > Unix. This should probably be on the list of frequently asked questions. I'm not an expert, but here's my answer: The IDE drives are good, and as far as an AT-386 class machine is concerned, they are identical in interfacing terms to an ST-506 (ie. normal) hard disk controller/drive. The nice thing about IDE is that they are simple to install, simple to setup, and they are appreciably faster than the ST-506 in some cases, especially the IDE Conner 200MB drive, which is a peach of a drive. An IDE drive will work under any unix so long as the drives parameters (heads, sectors etc) appear in that unixes tables, or the unix lets you enter your own drive specifications. In DOS, no special drivers are required, so they are much less hassle than a SCSI disk. Asking for the difference in performance between IDE and SCSI is a little unfair: The drawback of IDE is that you are stuck with what controller hardware the drive manufacturer puts on their hard disk, since the bus card basically contains only a small amount of buffering circiutry. SCSI, on the other hand, varies enourmously according to what controller you are using. With a basic SCSI controller, the difference in performance between IDE and SCSI is probably negligable. However, you can purchase some very sophisticated intelligent SCSI cards (Adaptec, SCSI-2000, ...) which will increase your performance dramatically, and take SCSI into a different league from IDE. These SCSI cards often provide UNIX/DOS drivers for things like tape drives, CD roms, worm drives and more. As a consequence, they are much harder to set up, install, etc. but give you greater flexibility. Of course, these controllers cost a bit as well. Which to get? I think you'd be happy with an IDE, unless you have some demanding computing to do, or are about to add lots of drives/tapes to your machine. You can always get SCSI later, and use it as well as IDE in your machine. You could get a basic SCSI card and drive, and upgrade your card at a later date. But be prepared for hassle with SCSI - make sure your card is supported by the relevant unix system. Jon. PS. For the record, I have a 100MB Conner IDE drive and a 100MB Seagate SCSI drive with a WD-7000-FAST controller. No, I'm not telling you which I prefer! In any case the AT BUS has a lowish bandwidth, so