toma@tekgvs.TEK.COM (Tom Almy) (12/18/87)
I just recently got the FB+ upgrade from FB, and compared the performance.
My system has a 16 Mhz 80386, a single high density floppy drive (used for
the backups), and a 100+ megabyte hard disk with about 40msec average
access. I use vcache to cache the hard disk (1 meg cache size) and
Vfeature Deluxe to carve the drive into 3 40 megabyte partitions. OS is
PC DOS 3.1, 15 buffers are specified, and the cache is flushed prior to tests.
In the following cases I backed up my smallest utilized partition, containing
8,314,880 bytes of user files (as reported by chkdsk and FASTBACK). I
exchanged floppies as fast as I could when the speaker beeped.
Of particular importance is that most files in my directories are archive
files (.ARC), and being already compressed might not benefit from the
compression of FASTBACK+. So this test constitutes a worst case of file
mix (but very good hardware).
FASTBACK (blank disks): time=8:01, 7 disks (36 tracks on last disk).
FASTBACK (formatted disks): time=4:56
FASTBACK+ (blank disks): time=9:02, 7 disks (5 tracks on last disk).
FASTBACK+ (formatted disks): time=4:40, 7 disks (10 tracks on last disk).
FASTBACK+ compresses files only if it has time. Since it had more time
when it was formatting, it took less space on blank disks! Slower machines
will produce worse results. There is an option for maximum compression
which will compress even if it causes the floppy to wait. Using this
I got time=4:18, and 6 diskettes, actually saving time!
FASTBACK+ reported 7,673kb as the size of the files (?). It also has
a feature that predicts disk usage and time. The prediction was 7 diskettes
and 4:16. It is interesting that the package wrapper claims
"10 Megabytes / 4 Minutes" when the program predicts "7.6 Megabytes / 4+
Minutes". I assume the marketeer and the programmer never talked to each
other!
My conclusion is that, for me at least, FASTBACK+ is no faster than FASTBACK.
I would like to hear from any upgraders that got the 2x speedup claimed!
I am glad I got the upgrade because the new program does have some nice
(make that *VERY* nice) added features:
1. Uses standard DOS format disks.
2. Can easily specify files to include/exclude in backups and
in restores. Displays directory heirarchies to help out, and
will also illustrate the files selected without backing them
up.
3. Write the catalog file to the backup set. When it writes the
catalog file to disk, it gives it a unique name so that it
doesn't erase the old (great for multi-volume users).
4. Estimates backup time and (apparently worst case) disks needed.
Tom Almy
toma@tekgvs.TEK.COM
{...}!tektronix!tekgvs!toma
DISCLAIMER: I am not associated with Fifth Generation Systems in any way
accept as a satisfied customer.