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- From: ghg@en.ecn.purdue.edu (George Goble)
- Subject: Re: Tape drives (was Re: Dumping a Gigabyte)
- Message-ID: <1993Jan23.151946.20473@en.ecn.purdue.edu>
- Organization: Purdue University Engineering Computer Network
- References: <id.DZQW._25@ferranti.com> <1993Jan17.210451.14999@siemens.com> <1jhhuvINN4ei@lynx.unm.edu>
- Date: Sat, 23 Jan 93 15:19:46 GMT
- Lines: 30
-
- In article <1jhhuvINN4ei@lynx.unm.edu> sfreed@hydra.unm.edu (Steve Freed) writes:
- >In article <1993Jan17.210451.14999@siemens.com> aad@siemens.com (Anthony Datri) writes:
- >
- >> While DAT drives have certain appealing features, the fact remains that
- >> they're often abysmally slow. The Archive Python, for example, has a
- >> *peak* write speed of 183 K/s.
- >
- >Someone also mentioned that a minus was the low capacity (1.2 Gig.). I
- >recently saw one advertised that did 8 Gig. I'm not sure what the write
- >speed was, but I'm guessing it would be somewhere above 1 M/s based on
- >the above number. (It all depends on your compression ratio)
- >
- >I prefer DAT because 1) There is more than one manufacturer, I like
- >competition (the price is lower, more than one source), 2) Access speeds
- >are *much* quicker. (access as in "mt fsf 4" and "mt rew")
- >
-
- The "8 Gig" DAT, was probably from HP. It is advertised to be 2GB
- without compression. I tested one of those in compression mode.
- I repeatedly dd'd (51200 byte records), the system disk (420MB), system
- binaries + user files, no images or large areas of "zero" blocks,
- to the tape. The 8gig Dat held 3.1gig, and transfer rate was
- 18 meg/min. That was the long tape also (90m?).
-
- An Exabyte 8500, with a "screen door" (Peripheral Vision Co.)
- compression system, held 8.9GB (dumping the same disk), and
- had a transfer rate of around 60 meg/min. I know which one
- I am going to use.
-
- --ghg
-