General SCSI+DLT speed questions

(Hopefully this is on-topic since the technologies and hardware are over a decade old) Background: I rescued two DLT 7000 drives this weekend (one Quantum, one SUN) and hooked them up to an Adaptec 29160 HBA. The Adaptec has an external 50-pin (Ultra 2?) connector, so I used a 50-to-68 pin (Ultra wide SCSI?) cable to connect the HBA to the first DLT drive, and a 68-pin to connect both DLT drives together. It took a bit of configuring in the Adaptec BIOS (had all targets set to U160 16-bit) but after some sane reductions they both were recognized and speed was set to 10MB/s. My concern is that it takes nearly two hours to fill a DLT IV (35GB) tape, regardless of which drive I use or HBA settings I configure. The Quantum drive averages 4168 kB/s; the SUN drive is slower and averages 3355 kB/s. Are these times normal? With such large capacities per tape, I would have assumed they could be filled faster... They are reporting a 10MB/s speed, why am I getting only 4MB/s? Another question: Is it normal for DLT drives to go faster if compression is disabled? I thought the point of hardware compression was that it came without cost. I'm running a test now, but was curious to know if other drives were known for being "slower" with compression on. -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Help our electronic games project: http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/ A child borne of the home computer wars: http://trixter.wordpress.com/