CompuServe Thread

#Disk Stacker Software

11 messages in this thread
#9639From: Roger DanielsenFeb 22, 1992 11:06 PM
Presently I'm considering trying out some data compression software on a new disk drive I just ordered. I'm planning on using this disk drive for storing targa files to be laid to tape at a later date. Has anyone tried using data compression software with compressed targa file and/or a Diaquest controller (DQ-422)? Roger D.
#9657From: Matthew J. D'ErricoFeb 23, 1992 11:24 AM
Rojer — There are two kinds of "data compression" software: realtime and not. Based on your subj. heading, it sounds like you're looking at realtime compression, such as stacker, or somthing like it. I think you'll find that depending upon what application (and thus what version of .TGA) you'll only achieve a 10% compression at best. For the most part, I don't think you should plan on any savings if you're only interest is storing compressed TARGA files… The purpose of "compressed" TARGA and GIF is to give you the "realtime" compression buit-in to the file format, rather than external (on the disk). Non-Realtime compression utilities such as PKZIP, LHArc, etc… Offer a much higher compression ratio at a cost — speed. They don't run "realtime", but if you can live with that, you can expect better compression. Still, though, you can't expect more than say 30%, again, depending upon the version of TARGA (and the version of the archiver, they're constantly surpassing each other in performance and compression ratios)… Now, if you're looking to put "uncompressed" files on a stacker, or disk doubler drive… I recommend it highly. I'm personally running stacker on 2/3 of a 200MB disk. I have a "partition" (quotes intended) left "unstacked" for Windows SWAP, temp files, and yes, .ZIPs, .TGAs, and .GIFs… I have over 400MB of files on this 200MB drive, and I still have over 100MB reported free ! I don't suffer from any noticeable performance loss, and swear by the reliability. Hope this helps — — Matt
#9728From: Roger DanielsenFeb 24, 1992 5:40 PM
Matt, Yes, this helps a lot. One other question I've had is , can you perform disk maintenance with utilities such as PCTools "compress," "diskfix," etc. using a disk drive that's compressed with something like stacker? Roger D.
#9780From: Matthew J. D'ErricoFeb 25, 1992 12:57 PM
Rojer — Glad to help… You canNOT use disk compression/realignment/defragment utilities on a "stac'ed" drive — most of the newer utilities, e.g. : NORTON SpeedDisk at version 6, won't even recognize the drive… In cases where the defragmenter/compresser recognizes the drive, (NU @ 5.0), you may be doing more harm than good… The good news is that Stacker 2.0 comes with its own defragmenter (SDEFRAG) which does a fine job, although it's a little on the slow side. BUT ! Stacker also manages storage a bit differently than a regular drive, so the rate at which files become fragmented is SIGNIFICANTLY lower (a friend noticed this and ran a test — after 500 iterations of switching large files, a regular drive was 65% fragmented, and the stacker drive was only at 15% !)… Very efficient storage… As far as other tools, like disk maintenance, recovery, etc… They all seem to work just fine… Personally I still don't trust CentralPoint after the PCTools 7.0 fiasco, but I run Norton alot — NDD, UNERASE, DISKEDIT, DirectorySort — (I should emphasise: NOT because of a problem, but for other reasons) — and get exactly what I expect from these tools… Oh, and to add to the "CSA" response strand of this thread, you CAN indeed store "compressed" files (those compressed with "offline" compression utilities) on a stacker drive (and others)… I don't do it myself as a matter of preference… What will happen is that you won't realize any disk space savings (1:1), and the reported free space will decrease by a factor of two because of it… (for example, if stacker reports 10MB free, and you write out a 2.5MB "compressed" file, you'll only have 5MB left)… Remember, TARGA comes UNcompressed, and compressed at different levels depending upon the tool's release level of the .TGA format. Regards — — Matt
#9809From: Roger DanielsenFeb 25, 1992 11:11 PM
Matthew, This is exactly the information I was looking for. Thanks. Roger D.
#9668From: CSA/CAFeb 23, 1992 4:45 PM
Roger, I can't vouch for Stacker's performance on .TGA files, but PKZIP will often do a good job of non-destructive (lossless) compression. It is also possible to perform lossy compression (still looks good, but not a 1:1 pixel match) through software using Telephoto's Alice compression software (I'd stick to about 20:1 compression, 100:1 gets a little boxy). Kevin Krell – Computer Support Associates
#9729From: Roger DanielsenFeb 24, 1992 5:40 PM
Kevin, Seeing as though I don't have a VTR I'm rendering to disk and dumping to tape at a later date. What I'm trying to do is render targa based animations so that when I bring the tape deck and go to tape I make the most efficient use of the time I have with the deck. So I guess my question is using a utility like Stacker, do you know if I will be causing myself any problems using the disk to VTR interface of the Diaquest in 3D Studio? Even a 10% improvement may be of some use. Roger D.
#9742From: CSA/CAFeb 24, 1992 7:52 PM
Roger, The files end up looking identical to the software. If you want to save them to a Stacker partition, that's just fine – they'll just take up less space on your disk. Kevin Krell – Computer Support Associates
#9798From: Roger DanielsenFeb 25, 1992 7:20 PM
Thanks, Kevin.
#9945From: John Sergneri [ADESK]Feb 28, 1992 11:52 AM
Kevin, I'd like to get in touch with Telephoto. Can you upload an address/phone number? Thanks, JS
#9953From: CSA/CAFeb 28, 1992 1:43 PM
John, Telephoto Communications, Inc. 11722-D Sorrento Valley Road San Diego, CA 92121-1084 619/452-0903 attn: Len Roberts Kevin Krell – Computer Support Associates