Tekram SCSI Problems

[Bombelek]

Im really new to SCSI so I hope you will forgive me guys if I write something stupid
Anyways here is my (to me) strange problem, my IBM 36LZX drive is really slow. When I benchmark it I get very poor scores. Im using a Tekram DC-390U3W SCSI-card and and the LVD-cable that came in the Tekram package. The cable is terminated in the end and the IBM is terminated as well. In the SCSI-BIOS I have tried every setting available and it seems as if it doesn´t matter if it´s running in U160 or even SCSI1. The speed remains the same (about 41MB/s Buffered Read). I have tried am both Tekram drivers and LSI drivers (the card is using a LSI controller-chip). When using a SCSI-Wide (i hope thats the proper name for it) cable the drive acts very strange only allowing the computer to read its contents but not to write anything on it.

I really would apriciate all the help i can get. This bad performance is getting on my nerves..

Im running Win2K SP2 on:
AMD K7 900
256MB PC-133 CAS2
ASUS A7V (bios 1008b1)

 

[Jhereg]

If the end of the SCSI chain is terminated , no need to terminate the drive !
take off the drive termination and it should be much smoother

 

[Bombelek]

Well, I have a quick update to make..
When removing the temination on the IBM the computer went nuts. After verifying the drive in the SCSI BIOS it found 5 bad blocks. And the performance is unchanged.
HELP ME DAMNIT!

 

[ple88]

i'm a bit confused by your setup. ibm ultra 160 drives (all lvd drives as far as i know, for that matter) don't have termination built in. so how did you terminate the drive?

my guess is that when you "removed" termination from the drive, you removed or altered something else.

the correct setup for this drive is to terminate the end of the cable using the terminator supplied with your controller. your scsi controller (tekram) has the proper termination built in for the other end of the chain. it really isn't possible to terminate the lvd drive itself. (this is unlike many other scsi devices which do have an option for termination, which should be disabled if you're terminatng the end of the cable with a discrete terminator)

the only other thing you may need to do is add the correct miniport driver. this would depend on your operating system and whether or not it's already built in...check the tekram docs or web site for the specifics of your installation. probably wouldn't make much difference, though, so i'm wondering just how bad is your performance. Ultra 160 refers to the bandwidth of the scsi chain. You're not going to get anything close to that from a single drive.

 

[Bombelek]

The IBM drive is a 37LZX (9GB). It has a 68pin connector. On the drive there is a jumper-setting called termination, wich i guess is to be used when using a SCSI-Wide interface. Im not really sure though. The documentation i got with the tekram controller is not very big. When i first installed the IBM drive i used another cable that came bundled with the controller (ie. Ultra Wide Cable) wich has three connectors. The performance was great back then. SANDRA scores were good (better than UDMA66 drives you can compare with). After i reinstalled Win2K the drive went nuts. Someone told me that I should use the LVD cable and the drive worked again but with very poor performance (SANDRA score was comparable with a 5400rpm drive running PIO4).
I use the miniport driver suplied by Tekram. The CD-Rom on the other channel (B) is working great but the drive is acting very strange.

P.S; I have not altered anything after i reinstalled windows. I just made the computer boot SCSI first but i cant see why that should make any difference.

 

[mastertech01]

<< 41MB/s Buffered Read >>



First off that is an excellent speed for any SCSI drive.. 45MBPS is the best average the X15 gets.. I would consider myself extremely lucky.

Secondly your drive is an LVD drive, and has no onboard termination, so you are likely totally lost in what you are doing. I would suggest that you go to the IBM site and READ the jumper settings for your drive. In most cases you wont need to touch any of the jumpers. If you mess with the wrong ones it will SERIOUSLY affect drive performance. Most SCSI U160 drives bench with Sisoft in the UDMA66 range, as the Sisoft score are seriously BLOATED for IDE performance.

Always use an LVD device with the supplied LVD cable and terminator. All you should need to touch on the drive itself are the ID jumpers and only if you are not booting to ID 0. Ensure you are connected to the LVD connector on the controller, and in Bios of the controller enable wide negotiation, and synchronous transfers.. basicly most controllers default to the correct settings for U160 LVD operation. If your cable is not a true LVD cable with a true LVD terminator you could get tremendous error problems. Correct all your configuration and settings, check the jumper settings with the IBM tech support pages for your drive, and all should be well.. of course if you corrupted the drive a Low level format from the controller bios might be necessary. Set the controller for auto termination and ensure all SCSI channels are properly terminated..IE the 50 pin device needs to be terminated at the end of the chain.

SCSI can be real easy to use, or a real pain in the arse if you dont know what you are doing and just start throwing on jumpers cause they LOOK like they fit.
Check out Garys SCSI FAQ too.. it has many good pointers on it.. you will find it with a simple web search.. also check out www.storagereview.com..

Good luck

PS.. AND MAKE SURE YOUR CONTROLLER IS ON A BUSS MASTERED PCI SLOT NOT SHARING WITH ANOTHER MASTERED DEVICE ON ANOTHER SLOT AND TEKRAMS DO NOT LIKE TO BE RUN AT HIGH FSB!