🚀 go-pugleaf

First, you really shouldn't cross post to so many different newsgroup.

A comparison of SCSI and IDE can be rather long and drawn out depending out which
phase of the technology your at with each. Instead, I'll just go over the highlights
and let other who so desire dive into the gory details.

Typically SCSI has always been faster than IDE (Currently it's 160MB/s versus 100
MB/s), offered more devices than IDE (15 to 7) and had little impact on CPU usage (5%
versus 75%). With new technologies like UDMA and the ability to add multiple IDE
cards, you can now come pretty close to matching SCSI functions and performance.

SCSI also tends to be more expensive then IDE, partly because of it's advantages and
partly because SCSI devices have a longer mean time between Failure\repair
(MTBF\MTBR). SCSI cards are able to multi process, meaning they can carry out
multiple I/O request at a time, IDE, I believe, is still serial based meaning I/O
request line up. You also need an OS like Win NT/2000/Linux to be able to take
advantage of Multi process I/Os

With a normal PC, you can have 4 IDE devices. With any SCSI card you can have at
least 7 and with new cards 15 devices. SCSI pretty much always gives you external
connectors (as you probably won't find many cases that support 15 devices) SCSI also
tend to have the larger drives first, but it seems in the last year or so, IDEs are
really screaming by.

SCSI allows you to go greater distances. Depending on the technologies in use, the
SCSI devices could be from 6 meters to 25 meters from the PC. SCSI allows you to
share SCSI Buses, which is used in the cluster world to allow 2 or more PCs to access
the same disks or at least the same disks arrays.

Until recently, SCSI was the only technology that offered hardware RAID features.
(RAID is a subject in itself) Though most home users have never had a real need for
it, and the cost for a hardware raid controller is normally not worth the minimal
benefits (again, for a average home user). SCSI controllers also tend to have fairly
large amounts of cache (or memory) on them. Most standard controllers today have
between 32 to 64 megs of ram, with the big boys have as much as a gig of ram., of
course, the cost for a 64 meg SCSI RAID controller is around $1000-3000, depending on
the technology it deploys.

SCSI is ideal in environments that needs fast large disks, performing heavy read and
write request. For more home users, there is very little reason to go to SCSI because
the cost is so much more than the gain, especially running in the Win9x world. But if
you wanted to create a 400 Gig disks volume at the hardware level, then SCSI would be
the perfect technology.

Again, this is just kinda of skimming the surface, and their are plenty of variables
to this. If you really want to know more, I would start at www.Adaptec.com and do a
few searches on SCSI vs. IDE and RAID. Plenty of reading.

HTH

Dale


"Holy Smoke" <kissme@columbus.rr.com> wrote in message
news:cNYj7.37727$Iq4.18664937@typhoon.columbus.rr.com...
> Can you tell me the difference between them? what is their advantage, and
> disadvantage?
> what can scsi do that ide cant? (sorry, hehe, i need more info about scsi,
> know enough of ide)
>
> X-Post?
>
>