re help adding a scsi drive can it coexist with an ide eric bosco ebosco us oracle com wrote first of all please edit your postings wading through lines of quoted crud which people have already read makes people much less likely to help you of course if you don t want to be helped that s your problem is this true i was under the impression that people on the net had both scsi and ide working together no it s not true you can get scsi and ide to work together but there are restrictions at least with the adaptec you must boot from the ide drive there is no way to boot from the scsi drive if you have both ide and scsi drives you must disable the scsi rom bios i m not sure about this though and so you must also use some special drivers to access the scsi drive hmm i know that you have to disable something related to the scsi bios but i m not sure if it is the rom itself back in february someone asked about ide and scsi this question gets asked again and again at the end of this message i ve included an edited copy of my reply you might find it interesting darryl okahata internet darrylo sr hp com disclaimer this message is the author s personal opinion and does not constitute the support opinion or policy of hewlett packard or of the little green men that have been following him all day is it worth it to get scsi over ide will there be a noticable decrease in access time increase in xfer rate for msdos applications isa based scsi and ide controllers generally have comparable throughput you might get slightly higher throughput with a scsi disk but you ll also pay more for the disk and up in some cases you ll also pay much much more for a good scsi controller note that good scsi controllers really show their power if they re used with a good multitasking operating system like a pc unix unfortunately neither msdos nor windows is a good multitasking operating system the performance advantage of scsi controllers is mostly wasted with these which leaves the advantage of being able to connect multiple devices to the scsi bus as the only advantage however note that you can expect to pay a premium for scsi devices if you re only going to be using msdos stick with ide it s cheaper and you ll have less headaches will virtually any scsi device chain into the controller for my hard drive bernoulli box cd rom tape drive etc note the following is true for msdos windows only who knows what the future holds for windows nt and unix no generally you have to find drivers for each scsi device which probably don t exist unless you re using one of the better high performance scsi controllers these are typically bus mastering scsi controllers that cost around street prices and up and drivers that allow you to connect these controllers to popular name brand scsi devices either come with the card or can be purchased for under list price examples of such driver kits are adaptec s ez scsi kit list this works only with adaptec scsi controllers corelscsi from the same people who make coreldraw list this driver kit will supposedly work with any scsi controller card that has an aspi driver like the adaptec central point s pc tools for dos supports a number of scsi tape drives the documentation lists tape drives unfortunately it works only with adaptec controllers are there likely to be other problems incompatibilities with a scsi controller and sound cards video accelerators and similar equipment yes you will run into problems if you re using a high performance bus mastering scsi controller this doesn t sound right doesn t it it s true though with one of these controllers you ll probably have to tweak your system to get it to work with sound cards floppy controller based tape drives like the cms jumbo and windows i know i ve been to h ll and back getting my scsi controller to work with various hardware software thank god for tape backups if you want a copy of my adaptec hints and tips file send email these problems aren t really the fault of the scsi controller card the problems are really with the general hardware and software design of the pc e g no standards however adding a bus mastering scsi card is what brings these problems to the surface and makes them visible scsi holds a lot of promise but you can run into a lot of pc compatibility problems if you re planning on using only msdos windows stick with ide if you want to use windows nt or a pc unix you ll have to make some hard decisions a good scsi controller and more than one scsi hard disk will probably give you excellent performance at the possible cost of msdos compatibility i say probably because while i know this to be true with a pc unix i don t know if this really will be true of windows nt i suspect that it will but i don t know for sure
