SCSI Ports, what do they do?

to elaborate, SCSI devices can be daisy-chained off one another and all work independently of each other.  Each scsi device must have a unique scsi id, per controller, which allows for it to interact with you machine.  The scsi controller has its own bios, which is not dependent on the machines bios.  Therefore, you could hook a very large drive up to a machine that doesn't support large drives.

jhance is correct, the external port is used to hook up scanners, tape backups, scanners, cdrw, etc, etc, etc.  

The other advantage of scsi, and probably the primary use of it, is the ability to write to multiple drives at the same time, and its super fast.

> its super fast.

However, ATA66 and ATA100 hard-drives and controllers
have considerably narrowed that performance-advantage,
when compared to pre-UDMA (PIO -- programmed I/O) hard-drives
of a few years ago.

Scsi is faster for two reasons.  Throughput is higher and there is less demands put on the CPU.

Do your homework.  Buying SCSI devices can be like buying tires for your car.  They may look like a great deal but if it doesn't fit your rims it's of no use.

There are different connectors.
Scsi I, II, III, wide, Ultra wide, Ultra2, LVD and combinations and permutations of these.
There are adaptors for the different pin outs.  Some need power some don't.  Which way can you convert?

If there is a site that explains this clearly maybe someone can provide it.  I haven't seen it yet.

> If there is a site that explains this clearly maybe someone can provide it. I haven't seen it yet.

Sites like http://WWW.TomsHardware.COM
have many tutorials on many topics.  Try looking there.

Dont be mislead: The SCSI interface isn't so usefull for the regular user. The SCSI disks are 2X more expensive that the adequate ATA disks and they aren't faster than the new ATA100 disks. The modern scanners comes with USB ports (like all new ink-jet printers) ant this is faster that SCSI. More of the new MB (from ABIT - KT7-raid, MSI and so one) comes with additional ATA 100 RAID controller. The SCSI interfase is usefull for the network servers, not for the single user.

You have 2 50-pin D-Connectors on the back of your computer? Must be an expansion card which gives these SCSI connectors. I suppose you are fine until you have to redo the system: I would not even use these connectors unless I had the driver for that card as a back-up. Think about it: do not invest the time and money on SCSI unless you can effectively revert to it's original configuration. Remember, even that card needs drivers during a hard problem. Perhaps not an issue here, but worth mentioning before you go further.

Hi all,

This question has been open for quite awhile. I am going to allow feedback from the questioner and experts. If it is not resolved, I will delete or accept an answer based on the info I have been given. Experts, feel free to offer input. I will monitor this question for a period of 5-7 days and come back and evaluate the situation.

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ComTech
Community Support Moderator

Assuming that the two connectors really were SCSI, not USB,
JHANCE was first with the correct answer.

Agreed, jhance will be awarded the question, as the author never returned.

ComTech
Community Support Moderator