Re: RamFAST & GS/OS cache

[hal@budapest.math.macalstr.edu (Harold Byron Bouma)]

Frank M. Lin writes
> Now that I've got my self a CD-ROM drive, it's pretty obvious that the  
current
> RamFAST driver isn't doing a great job at directory caching.
> 
> It really shows with the CD-ROM drive.  I mean, since the drive's access time
> is slow, I can tell that lot of the time is spent on reading the directory.
> After the directory is read, it looses it pretty fast...  if I close like 2
> or 3 folders, and then try to go back, it would be re-reading it.
> 
> Questions...
> 
> 1. How smart is the GS/OS cache??  Does it know when to flush the cache if  
the
> directory information has been changed?
>
> 2. What does it cache anyway?  Does it cache both the data and the directory
> tree or just the directory tree?

	GS/OS also caches directory information as well as data. And if GS/OS  
is a good OS, it should flush the directory information right after its been  
modified. RAMFast on the other hand just caches everything that comes in its  
path, which is not nearly as smart as GS/OS's caching.

> 3. This sort of relates to question #2, how big should the cache be set?  I
> mean, if it just caches the directory, I think 64k or 128k should be enough.
> But if it caches data as well, then maybe more like 768k or 1024k...  I set 
> my to 768k right now.  Is it too big??  I guess it really doesn't matter, 
> because I'm using RF.

	No, you need GS/OS caching too because its very helpful when using the  
floppy. However, caches for the most part should be small. As cache sizes start  
to grow, its speed benifits start to decrese as the time maintaing the cache  
goes up. I find that 32K/64K is pretty good. Anything over that really doesn't  
help much, unless someone has some specs to disprove that - which I would like  
to hear about!! :)

> 3. Do all 16 bit programs benefit from GS/OS cache?  Do certain toolsets have
> to be started by the application?

	All Disk I/O benifits from GS/OS caching (unless you have a RAMFast)

> 4. Does the Apple II High-Speed SCSI card support GS/OS cache?

	Well, yes and no. Yes, GS/OS caching works to the card, but the card  
itself doesn't do it. The Apple Hi-Speed card does no caching which is why the  
RAMFast beats the daylights out of it.

> I am going to bug Drew to support GS/OS cache :)

	Good, you should. Its much better caching and the GS will improve from  
it. Even the Turbo IDE card does it as well.

| Hal Bouma                            | Send mail to: HBouma@Macalstr.edu    |
| Macalester College, St. Paul, MN.    | and           HBouma@Macalstr.Bitnet |
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