What difference?

[Mntsnow]

Thinking about Scuzzy tape backups...But there is 2 options....
Single ended or differental

1 what is the difference?
2 which is better?

All replys welcomed.

Thanks guys

Mntsnow

[LJE2]

Differential SCSI is an option for a single ended controller card that allow data to travel a greater distance at a greater speed, (with an external device you can use a longer cable up to 12 meters), the devices themselves usually don't cost more but the controller cards themselves are more expensive, in the case of Adaptec cards about twice as expensive, most SCSI cards that are differential are LVD (Low Voltage Differential) and these use the Ultra2 SCSI Bus allowing data transfer up to 80 MBytes/sec. doubling the previous burst rate.

[BBA]

I ran into this also: If you have a LVD Device and you accidentally connect it to a 'non' LVD device, you can and probably will damage one of the componants.

I generally treat the whole differential scheme as a incompatibility I must avoid, because having some differential and some not will lead to confusion and burnt up parts, one of which was already a dual P2 450 KAYAK motherboard!

BBA

[This message has been edited by BBA (edited 06-04-99).]

[Bleeding Edge]

To add a bit of clarity, or confusion...

LVD U2 drives come in both the 68-pin single-ended or the 80-pin differential.

When using a U2 controller (at least Adaptec's), the older devices don't interfere with LVD hard drives. A chipset on the board makes certain of that.

Since the LVD drives don't have terminating jumpers, a special cable that has a permanent terminator at one end is used.

I agree that the differential drives are more of a headache. But the single-ended LVD drives are like a sweet dream. After having one, you'll never want any other type of drive.

Well.. there is the fiber optic ones.

All this is beside the point, no? For a tape back-up?


BBA.
You really burned-up the HP?
Yikes!

[LJE2]

As BBA points out, they are not interchangable, and most SCSI devices at this point are NOT differential

[Mntsnow]

Thanks for the replys and "insightful" information....I think I will get a "single-ended" setup!

Thanks guys.

Mntsnow http://www.sysopt.com/forum/wink.gif

[BBA]

Yep! I was to put in a harddrive one of our users recieved. It turned out not to work, so we called the manufacturer, Seagate. We were told that we had recieved a differential type drive and it was not compatible with thecontroller and could cause damage to the controller (built into mb) if connected to it ( a little late I might add ).

We re-ordered a compatible drive and installed it when we got it, np. 2 weeks later the user called again, couldn't boot the PC at all, kept getting a 'OS not found'. The only way it would boot was to the NT cd.

The built in controller was taost!

Thats why I say dont do it unless you start out with no old drives/controllers and keep track of who installs what drives where!

BBA