Ultrix dump to TK50 not using entire tape?

[Dave Steffens]

We are running Ultrix version 1.1 on a uVAX II with TK50 cartridge tape drive.
When dumping our main filesystem to TK50 tape, we noticed that each cartridge
appears to hold only about 40Mb instead of its rated capacity of 95Mb.
What's going on here?

P.S. The TK50 is **very** slow -- it takes almost 3 hours to put 40Mb of dump
on the TK50 whereas it takes only about 45 minutes to put 40Mb of dump
on our ancient PDP11/34 magtape (Digidata 800bpi 45ips).
-- 
{harvard,mit-eddie,think}!eplunix!earvax!das	David Allan Steffens
243 Charles St., Boston, MA 02114		Eaton-Peabody Laboratory
(617) 523-7900 x2748				Mass. Eye & Ear Infirmary