scsi chain

[partime]

Hi ,
I have 3 lvd drives --- and a brand spanking new 19160 adaptec controller (upgraded from a ultra wide card) 2drives are capable of ultra 80 the other 160... I also bought a new cable with a terminator (vendor claiming its a lvd 160 compatible cable) my problem is when terminated the transfer rate reduces to 40 on ALL drives
when not terminated they post there proper transfer rates,,,but win2k reboots on its own .
the termination in the adapters bios is on auto
I suspect i have the wrong terminator for the cable

any thoughts???

and how do i tell?

[The Computer Valet]

Is this some kind of a RAID configuration.

I suppose what I would do is try _one_ drive. Terminate it and see if the transfer rate drops.

Try each drive in turn, if you can.

What do you think?

Cheers,

m

[partime]

tried that even single drives post low transfer rate when terminated

[DonJ]

You might check Adaptec's website for questions concerning "termination." You should be able to find what you're looking for...Good Luck!

[silencio]

Originally posted by DonJ
You might check Adaptec's website for questions concerning "termination." You should be able to find what you're looking for...Good Luck!

For everyone reading this, these two articles seemed to be the most useful.

1) For a LVD (Low-Voltage Differential) SCSI controller and devices:

A Multimode or LVD/SE terminator must be used.

- Do not use a Passive or Active terminators on an LVD SCSI bus, doing so will force the SCSI Bus to Single Ended mode. A Multimode termination provides differential impedance which is a requirement for LVD (Low Voltage Differential) communication on the SCSI bus.

- In most cases the Multimode or LVD/SE terminator will have some type of identification on them.

2) Question
... can an Ultra2 cable be used with the Ultra160 Adaptec SCSI Card?

This information applies to the following products:

Adaptec SCSI Card 39160, Adaptec SCSI Card 29160, Adaptec SCSI Card 29160LP, Adaptec SCSI Card 29160N, Adaptec SCSI Card 19160, Adaptec PowerDomain 39160, Adaptec PowerDomain 29160, Adaptec PowerDomain 29160N, Adaptec SCSI RAID-2100S, Adaptec SCSI RAID-3200S, Adaptec SCSI RAID-3400S

This information applies to the following Operating Systems:

N/A

Answer
The answer to your question is NO.

An Ultra2 cable, should never be used on the Ultra160 SCSI controller, do so will cause communication errors and possible data corruption.

The specification for the cable has changed between Ultra2 (80MB/s)and Ultra160 (160MB/s) technology. It is possible to use the newer Ultra 160 cable on an Ultra 2 SCSI card or drive, but not the reverse. An Ultra2 cable should never be used on an Ultra 160 SCSI card. It may work or at least appear to work and is possible to experience a lot of in-consistency / data corruption and data loss, sooner or later.

Note: It is also very important, that all components within the Ultra160 SCSI BUS, provide Ultra160 support and are Ultra160 compliant to include cables, connectors, drives, drive cages, and terminations. All of these are part of and effect the data transfer on the SCSI Bus.

Please review ASK article # 2004, just Click Here. This article address the question of the Adaptec SCSI card not having cables, when it is not purchased as a complete kit.

[partime]

thanks,
have read up on the lvd termination and discovered that the vendor had stated the cable was for ultra 160 w/terminator


plastic on the terminator has writing on it saying "active"
now I know this is wrong for lvd ,so I ordered a new terminator . Adaptec shoud explain this better in there manual

thanks again peeps!!!

[partime]

ok bought a new multi mode terminator - lvd+se

pluged that puppy into the end of my chain ( all lvd drives)
all drives posted there respective data rates
but.....
when I go to inatall any program in w2k the system reboots //
when I pull the new terminator and plug in an active one, the drives post an extream lower data rate but system is stable
whats up with that?

[silencio]

Could be the cable, could be the SCSI cages if you're using them, could be the drives or the card or one of those 80 to 68 pin converters if you're using one of those. I hate those. Try replacing the cheapest parts first.