RCST14@HEITHE5.BITNET (02/15/88)
Could someone please be so kind to tell me where I can get a decent disk
cache prg... The only things I want are: -working with a 4-part (C,D,E,F) HD,
-all FATS in ram (We've got 1 meg to play with guys!) -no side-effects like
disapearring HardDisks and annoyances like that.
I've not been able to find such a thing at UH-INFO nor PROG-A16... Maybe
one of you guys could post it to me? Thanx in advance :-)
Jan Joris Vereijken
Disclaimer: *NO* disclaimerThomas_E_Zerucha@cup.portal.com (02/18/88)
I don't know of any that just cache the FATS completely and the rest dynamically, but I have a short assembly program that increases the number of FAT buffers in GEMDOS - but I don't use it since Beckemeyer's Hard Disk Accelerator seems to do a good job all around. Optimizing the disk helps too.
gert@prls.UUCP (Gert Slavenburg) (02/20/88)
> ... but Beckemeyers hard disk accelerator seems to do a good job too ...
Can anybody that uses the hard disk accelerator (or the author) give us some
more information on what it does, especially :
1) Does it speed up reading solely (i.e. is it a 'write through' cache) ?
2) Does it solve the TEDIOUSLY SLOW writing problem on not too empty
partitions ?
3) Does it solve the 40 folder bug ? AND/OR
4) Does it work correctly with FOLDRxxx.PRG ?
5) (if the answer to 1 is NO) Does my hard disk file structure survive a
power outage occurring between writes (but with a non flushed cache).
Thanks in advance,
- a prospective customer -preston@felix.UUCP (Preston Bannister) (02/20/88)
From article <9232@prls.UUCP>, by gert@prls.UUCP (Gert Slavenburg): >> ... but Beckemeyers hard disk accelerator seems to do a good job too ... > > Can anybody that uses the hard disk accelerator (or the author) give us some > more information on what it does, especially : > > 1) Does it speed up reading solely (i.e. is it a 'write through' cache) ? It's write through. Writing _might_ be a shade faster (see following). > 2) Does it solve the TEDIOUSLY SLOW writing problem on not too empty > partitions ? Nope. It might help a little due to the FAT and directory tending to be cached, but the bulk of the slowness is in GEMDOS's FAT searching routine. > 3) Does it solve the 40 folder bug ? AND/OR Nope. > 4) Does it work correctly with FOLDRxxx.PRG ? Can't imagine why it wouldn't. I use GEMBOOT, which is similar to FOLDRxxx. -- Preston L. Bannister USENET : ucbvax!trwrb!felix!preston BIX : plb CompuServe : 71350,3505 GEnie : p.bannister
david@bdt.UUCP (David Beckemeyer) (02/23/88)
In article <9232@prls.UUCP> gert@prls.UUCP (Gert Slavenburg) writes: >> ... but Beckemeyers hard disk accelerator seems to do a good job too ... > >Can anybody that uses the hard disk accelerator (or the author) give us some >more information on what it does, especially : > > 1) Does it speed up reading solely (i.e. is it a 'write through' cache) ? Yes, it is 'write-through' cache. It doesn't always write-thru actually, but it *never* buffers the writes for later (i.e. it always physically writes to the disk). It attempts to make an intelligent decision about when to write-thru the cache (which costs the extra memory move), and when to simply dump the buffer. HD accel. is a "priority" LRU cache. The criteria that establishes "priority" are: a) is it FAT info? b) is it directory info? c) is it "a long way from the last head pos." Hd accel's main goal is to reduce those long seeks which are slow. Caching data on the ST is not as important becuase in fact the DMA rate for large data xfers is *faster* than a CPU block move. What costs is moving the disk heads. That's why FAT and directory info has priority over data. > > 2) Does it solve the TEDIOUSLY SLOW writing problem on not too empty > partitions ? Becuase HD accel. is write-thru, one might think that it is no help to writing files. But this is not true becuase TOS has to do a lot of reads of FATs and dir. info to write to a file. HD accel doesn't help a lot with the slow FAT searches, becuase this is more CPU bound with TOS, but it does help with writing. > > 3) Does it solve the 40 folder bug ? AND/OR No. It makes no attempt at this. > > 4) Does it work correctly with FOLDRxxx.PRG ? As far as we know, it works fine. If there are any problems, they have not been reported to us. There have been very few compatibility problems with HD accel. since Fall '86. The only known problem is with the new ICD disks (a bug in the ICD drivers). -- David Beckemeyer | "To understand ranch lingo all yuh Beckemeyer Development Tools | have to do is to know in advance what 478 Santa Clara Ave, Oakland, CA 94610 | the other feller means an' then pay UUCP: ...!ihnp4!hoptoad!bdt!david | no attention to what he says"