#CD-ROM cache questions
10 messages in this thread
Sounds to me as though your application is divided into data files and indexes;
where the indexes are the smaller files. By caching the index data, I think
you will be surprised at the performance improvements. As I have mentioned in
the past, we used a law application called CD LAW which improved dramatically
on search times. Using standard searches for the word 'tort' for example took
73 seconds without Speedway, less than 2 seconds with.
I'd recommend starting with 11-12 Meg. of hard disk space, and use a good
delayed write cache to support additional performance.
One of the major drawbacks on legal applications is that lawyers bill their
clients on time…by speeding up the app., the lawyer can't bill as much for
usage. Oh well….<g>
Reese.
Reese,
You didn't answer Bob's question about whether CD-S will have to re-cache (?)
the files each time the CD is changed. I think he would like to be able to
access files on one CD, switch to another, then switch back and still have
the original files cached (ie, without having to reload them).
What's the answer?
robin
Robin, that sounds good. It would be nice if the indexes could stay cached (or
take minimal time to reload). But that presents another question: Would the
application get confused if the indexes for one CD-ROM stayed in cache memory
when another CD-ROM was loaded?
–Bob
Sorry, The answer is no…you won't have to reload the cache when switching
disks. My apologies….was moving a bit fast this morning.
Reese.
Reese, another question. I read a file on CD-Speedway you uploaded to a LIb
here, and I believe you said that you discouraged use of Smartdrive. I have
Hyperdrive, a shareware cache, available to me. How does that work with
CD-Speedway? Is there another product that is preferable?
–Bob
Bob, are you sure you don't mean Hyperdisk? Hyperdisk is a product from our
previous developer Roger Cross. Hyperdisk is what FAST! was in 1989-1990. We
dumped the product for new development in FAST!.
The reason I don't like Smartdrv.exe or Smartdrv.sys is that you won't get FAT
table caching with that product. The easiest way to test this is to load an
exe file, then load it again. You should see the disk light both times with
Smartdrv. With a good cache like FAST!, PCKWIK, others, you won't see the light
the second time. It may seem simplistic and not all that important, but when
using products like Stacker or Speedway, your disk cache really becomes an
integral part of performance. The faster the disk cache, the better Speedway
will perform (if you are caching to hard disk). Obviously, if you're caching to
RAMdisk, the hard disk cache won't make a difference. However, let me
recommend a shareware product called Nifty James which supports XMS 32 bit
RAMdrives. It also extends out to 32 Meg. of RAM support for those with large
file needs.
Reese.
Reese, yup, you're right, I meant Hyperdisk. <g> Well, on your recommendation,
I've just ordered CD-Speedway and FAST! I'll probably be asking you for
assistance in fine-tuning them. Thanks!
–Bob
Bob,
Thanks for the vote of confidence. I'll be happy to help you.
Reese.
Reese, I can only bill for *productive* time <g>; time I spend staring at a
blank screen is time I can't legitimately bill for. So I'd just as soon speed
up the search.
I'd appreciate it if you could discuss the question of time required to
re-load the cache when switching disks. Thanks!
–Bob
See my reply to Robin, Bob. Sorry for the neglect.
Reese.