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SCSI ? need help please

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December 22, 2007 1:04:19 AM

Hi guys,
I'd be very grateful if You could share your input on this one.

Got a Fujitsu 73GB 10k 68pin 320 drive. And I'm not exactly sure if I can so easily get it to work in my system.
So far I think I'm missing a scsi controller and a scsi cable with terminator.
I have AHA-2940UW but I'm pretty sure that's not going to support the size of this HD - 73gb as I used it several years ago with 9.1gb seagate cheetah.
If I get a 19160 or 29160 will it work with this drive? What's the biggest HD 29160 supports?
and also do I need a new 160 scsi cable with termination or can I use the cable with active terminator I used with 2940UW?
Can I just use a 68 pin scsi cable without termination with this drive?


My system I believe is PCI 2.1 compliant so 29160 should work, it's a BrillianX IV Dual P3.
Thank You.

More about : scsi

December 22, 2007 8:30:59 PM

The size of the HD doesn't have anything to do with it - it's the interface.

The 2940UW is a single-ended (SE) SCSI controller, supporting 5MB-40MB (Ultra Wide) SCSI connections.

Your Fujitsu drive uses an LVD (low voltage differential) interface, which is very different. You need an LVD SCSI controller and cable.

The 29160 is a 160MB/sec LVD SCSI controller that will work with this drive. You will need the corresponding LVD cable, which has a built-in passive terminator on the end. Your existing cable will not work correctly, it is not designed for LVD use. LVD devices no longer are able to terminate the SCSI bus themselves using a jumper like older SCSI drives - the cable must contain its own terminator.
Related resources
a b G Storage
December 22, 2007 9:41:15 PM

^Agreed
December 23, 2007 2:03:25 AM

Thank You so much for Your help guys.
December 23, 2007 2:10:13 AM

So I understand there is no scsi bios limitation in regards to size of a hard drive like it it is in case of computer bioses and IDE in the past....?
So if I get a lets say 36gb or a 73gb scsi drive as long as it's Single Ended it should be supported fine by my 2940UW right?

Are scsi 160 and 320 HDs only LVD or can these drives be connected to a Single Ended controller ex. 2940UW?
What drive can I get to work with the 2940? cheetah, atlas, fujitsu?

Thanks again guys.
And thank You for the link to newer bios.
thanks much.
December 24, 2007 2:04:11 AM

Hi guys,
Isn't scsi backwards compatible? It is right?.

I just read that LVD is backwards compatible with Single Ended.
Therefore fujitsu 73gb 10k 68pin 320 should downgrade itself to 40 Single Ended ex. 2940UW, am I right?

On the other hand Sata II and Sata I are not compatible with IDE 33 through 133 as these are totaly different technologies.

I guess it would be possible that scsi 320 is backwards compatible with 160 and 80 only and not all the way down to 40, I'm not sure on this one at all, correct me please.

I used scsi before and I liked it. Now after several years I have a chance of going scsi again inexpensively. And I'm trying to do it the cheapest possible way. : )

If I'm totally wrong and can't connect the 73gb to the 2940UW then I have to go 29160 - 2.1 PCI compliant and I'm not sure if my PCI is a PCI 2.1 compliant. :o (
I'd also have to go with a new LVD 160 cable with a passive terminator as I'm told.
The cable I have now is a SCSI 3 (40) with an active terminator.

To sum it all up can I or can I not use the fujitsu 73gb 10k 68pin 320 drive with a 2940UW scsi 3 (40) and a SCSI 3 (40) 68pin cable with active termination for a Single Ended link?

Thank You greatly.
December 24, 2007 2:56:54 AM

SCSI is 100% backward compatible except for "high-voltage differential" (HVD), sometimes called just "differential". LVD is compatible with SE, narrow is compatible with wide (with a cable adapter).

You can connect your much newer LVD HDD to your SE controller and it'll work fine, just very slow. I'd suggest that you get at least a 29160 controller so you can run 160.

BTW, your system must be very old if it isn't PCI 2.1 compliant.

Hope this helps.
December 24, 2007 3:16:18 AM

you are certain this is a 2940UW?

I am not accusing you of not knowing your own hardware it's just a simple question heh..

BTW whats the model # on the drive?
December 24, 2007 3:28:08 AM

If all else fails a 2940U2W a cheap card and you can plug anything into it. Plus it allows 80mb/s transfer rates. Can be found easily....etc etc
December 24, 2007 4:09:27 AM

Hi guys,
thanks for all the help,

The model # of the fujitsu 73gb 10k 68 320 is MAT3073NP.

Yah, I double checked the SCSI controller, it is a 2940UW.
I have that in one system and a 7880 built into the motherboard in another system. They are pretty similar.

Yes, the systems are old, built in '98. One is a Dual PIII 600 and the other is a PIII 933, both on a 440BX chipset.

thanks guys.


If the drive is LVD I can still connect it to an SE controller, ex. 2940UW right? You just said that I think.
December 24, 2007 4:52:27 AM

Yes, you can connect them. You need a 68-pin SCSI cable connecting the controller in the middle, the disk in the middle and a terminator on the other end. The cable can be no longer than 3 meters. The HDD will discover that the controller is doing SE signaling and fall back to SE itself.

Here's a good reference page on SCSI: http://store.a2zcable.com/sccahetofscc.html
December 25, 2007 3:53:18 AM

Technically, an LVD SCSI device can indeed run single-ended. But you don't want to do that, because:

1. The single-ended SCSI bus is limited to 40MB/sec. This is far below what your Fujitsu hard drive is capable of working at. (Which is probably in the 70-80MB/sec range).
2. The cable length limitation for a single-ended 20MHz (40MB/sec) SCSI is 3 meters with a controller and a single device, or 1.5 meters with a controller and more than one device. This includes any SCSI cabling that's on the same bus, including inside and outside the case.
3. Single-ended SCSI is subject to more interference and potential cabling noise problems that result in errors than LVD is, especially in today's cases where many high-frequency high-power devices are operating.
4. If one device on the bus is operating in single-ended mode, then all devices have to operate in single-ended mode, limiting speed to 40MB/sec.
5. Perfectly working Adaptec 29160 SCSI cards are available on eBay (some even are models with PCI-X interfaces) in the $20-$30 range, which is a steal.
!