bsmith@mprvaxa.UUCP (Brian Smith) (01/10/87)
I'm interested in getting a disk caching program (Lightning, Flash, Vcache, et al) for my PC. I've tried EMMCACHE, which was posted on Usenet, but the speed improvement I've experienced has been slight. Therefore, I would like to hear about some of the commercial packages available. The major points I'm interested in are: - Is the program reliable? - Does it speed up access to both hard and floppy disks? - Does it use EMS (Aboveboard) memory? - Does it do full-track buffering? - How much conventional memory does it gobble up? - Does it have any bells or whistles? Please send any respones directly to me. (You should be able to find the appropriate path in the UUCP-supplied header of this message.) Given more than one or two responses, I will post a summary.
wtm@neoucom.UUCP (Bill Mayhew) (01/14/87)
I borrowed a copy of "lightning" from a friend to try out on my AT-compatible Epson Equity III. I set it up with a 128K buffer size for the cache. I found that in everyday use, the improvement in percieved performace was minimal, if any. For example, without lighting running, I ran DISKTIME.COM and came up with a throughput rate of 122,000 bytes/second on the fixed disk. With lightning, using a 128K cache, the throughput dropped to 92,000 bytes/second. Thus for long xfers of data that are bigger than the area that you reserve for the cache, you actually get a substantial decrease in performace. Lightning would be relatively useful for a database program that did lots of transfers of data in and out of files that were small enough to reside in the cache buffer. They include a demo file that illustrates this point nicely. Lightning would also be a welcome addition if you are not lucky enough to have a fixed disk on your system, as it does improved the percieved performance on floppies quite a bit. Oh yes, I didn't think lightning was enough of a value to warrant its purchase in my case, so I used Norton's wipefile to avoid being a pirate (for any of you sensitive readers out there). --Bill
harris@ecsvax.UUCP (Mark Harris) (01/15/87)
In article <360@neoucom.UUCP>, wtm@neoucom.UUCP (Bill Mayhew) writes: > > For example, without lighting running, I ran DISKTIME.COM and came > up with a throughput rate of 122,000 bytes/second on the fixed > disk. With lightning, using a 128K cache, the throughput dropped > to 92,000 bytes/second. Lightning automatically recognizes expanded memory boards (EMS or EEMS). I set aside 600K and I get a dramatic improvement in performance - except for data file updates my drive light hardly ever comes on. If you can afford this large a chunk of memory you get a lot more utility than with a RAM disk. Mark Harris, Appalachian State University
news@cit-vax.Caltech.Edu (Usenet netnews) (01/15/87)
Organization : California Institute of Technology Keywords: From: tim@tomcat.Caltech.Edu (Tim Kay) Path: tomcat!tim In article <360@neoucom.UUCP> wtm@neoucom.UUCP (Bill Mayhew) writes: > >Thus for long xfers of data that are bigger than the area that you >reserve for the cache, you actually get a substantial decrease in >performace. > If you type L HELP for lightning, it lists an option L M=n Limits Lightning read requests to n or fewer sectors Perhaps they included this option so that you aren't penalized for its use. I am using their 80286 card with Lightning, and Lightning is very helpful. Timothy L. Kay tim@csvax.caltech.edu Department of Computer Science Caltech, 256-80 Pasadena, CA 91125
gobbel@parcvax.Xerox.COM (Randy Gobbel) (01/20/87)
I've been using Super PC-Kwik, from Multisoft, Beaverton, OR, and have been quite pleased. My computer is a Toshiba 1100+ Laptop with very slow floppy drives, so the speedup is a major help. The program has almost every conceivable option for various hardware configurations, cache granularity, drives to cache/not cache, etc. The program includes a "measure" command that tells you the cache hit rate, which seems to vary from around 40% to over 80% depending on what I'm doing. One caveat: you do need to be careful about configuring the whole system so that the cache and your application aren't fighting over memory - i.e., you should either have a big cache and few buffers, or lots of buffers and a small cache, but not both, or you actually end up with worse performance. Multisoft's number is (503)642-7108. The program seems to be sort of hard to find, but I think it's worth looking for. (I have no connection with this company.) -Randy