#AMI BIOS & CACHE?
10 messages in this thread
PMJI, but with my version of DOS 5.0 write-back cacheing is the default, and I
have to go through two seperate command line backflips to disable it.
John Tissavary (LUNA cie)
John,
I don't know what you're doing to disable it but I have two DOS 5 books, one
from Microsoft and one from Dan Gookin and neither mention switches to disable
it. FWIW
-JE
John,
>> …and neither mention switches to disable it.
I had smartdrive running with dos 5.0 for ages, without writeback
cache. My previous message to you explains how to disable it (it WAS in the
gateway dos manual). … guess it doesn't matter with the new one out though.
David
David,
I believe you! The problems I've had with SMARTDRV however have been with
delayed writes as opposed to write only. I didn't mention it before but I use
FAST cache and also have PC-CACHE and LAN Cache all of which I like better than
SMARTDRV. FWIW.
-JE
John,
>> The problems I've had with SMARTDRV however have been with delayed writes as
opposed to write only
Sorry, but I'm a bit confused (and I hate being confused). Smartdrive
will either cache data headed for the disk (which inherently means a delay
before getting there), or it won't. What do you mean by "as opposed to write
only"? Or did you mean to say "read only"? When using smartdrive with write
cache disabled, there is no delay in getting data to the disk.
Just curious.
David
PS. how do you like Fast Cache? Is this the Norton one, or is that speedcache?
David,
A standard "read" with "write" enabled, reads and writes to the disk
automatically, the cache being a buffer. This is the default for SMARTDRV for
DOS ver 5.0. With DOS 6 this can be enabled with the /F switch which is also
the default. A "delayed write" can be designated with a /N "writes cached data
when the system is idle." This is the fastest cache but has the greatest risk.
There is also a similar "write" called a "staged write." The staged write is a
timed write, specified by the operator. This is not available with SMARTDRV.
Another delayed write is for SMARTDV; is activated with /C, which is for cached
disks. This not only writes to the cached disk but also insures that the data
is physically written. /N on the other hand will write to the disk but if the
disk is cached, the data stays in the cache until either the drive physically
loads it after a specified time or new data has pushed it through, or a /C
command is instituted by the operator. If you use the /C switch, whenever you
do a control-alt-del it makes sure that data is physically written to the disk.
However if you just power down and have a cached disk, you run the risk of
losing the data. You can also use the /R switch which clears the contents of
the cache, "including writing all write-cached information to disk, and
restarts SMARTDRV." All this stuff is documented in the DOS 6.2 Help file.
Often there is a problem with SMARTDRV, EMM386 with Write enabled and certain
SCSI or EDSI drives. Enabling Double Buffering will solve the problem.
However this is not a problem when one just uses HIMEM.SYS. The obvious
drawback is that your applications have to support extended memory and that
without EMM386 you can't load drivers high unless you use a memory manager like
QEMM.
Fast! Cache has several other options. It can be setup for extended or expanded
memory specifically. It also allows you to do "staged writes."
As every system is different, like some IDE and SCSI controllers have seperate
internal cache built into their controllers, or external cache on their bus
interface cards there is no one solution. Most IDE and SCSI have EDSI built
into their electronics which make them incompatible with SMARTDRV when used
with EMM386 and "write" enabled. Double Buffering may provide a solution. The
other solution is of course to turn "write" off.
-JE
John,
>>… writes to the disk automatically, the cache being a buffer. This is the
default for SMARTDRV for DOS ver 5.0. With DOS 6 this can be enabled with the
/F switch…
With the old Smartdrive, the only write option is on or off, and the manual
states "…writes information from memory to disk at times when other disk
activity has slowed." And it cautions "Check that smartdrive has completed all
write caching before turning your computer off… (with /C)". The new switch
/F "writes cached data after each command completes" not "when other disk
activity has slowed", so my whole point here is that the OLD smartdrive did
delay the writes to some point, and did not write to disk after each command
automatically, like the new one has the ability to do. I really haven't payed
much attention to the new write options since I run it as simple as can be,
smartdrv /x, read – yes, write – no, period. I just don't trust write caching
at all.
David
David,
I looked through the DOS 5 manual and could find no reference to
>> and the manual states "… writes information from memory to disk at times
when other disk activity is slowed." <<
Nor could I find a reference to
>> Check that smartdrive has completed all write caching before turning your
computer off… (with /C) <<
On what page number are these statements made?
Both of these statements are made with regard to the DOS 6.2 version and the
delayed write SMARTDRV /C option. Could you have confused the two?
I did find a reference to the DOS 5 SMARTDRV that states;
"SMARTDrive always copies new or modified information to the hard disk, so
there is no danger of losing data when you turn off your computer."
Directly afterwards in a NOTE it states:
" The version of SMARTDrive that comes with MS-DOS version 5.0 supersedes the
version that comes with Microsoft Windows version 3.0. If you have both MS-DOS
5.0 and Windows 3.0, use the version of SMARTDrive that comes with MS-DOS."
Is it possible that you were using the older Windows version?
-JE
John,
>>Is it possible that you were using the older Windows version?
I was using the version that came with Win 3.1. This was on a system
that I sold about 9 months ago, and my Dos 5 manual went with it. The following
quotes are from my Gateway 2000 windows 3.1 manual under the parameter
descriptions, and are the only references to write caching. This is the same
thing that was in my dos 5.0 manual, however that was a Gateway OEM manual as
well.
"+|- Enable (+) or disable(-) caching. Use the plus (+) and minus (-) signs
to override the default settings. If you specify a drive letter without a plus
or minus sign, read caching is enabled and write caching is disabled. If you
specify a drive letter followed by a plus sign (+), read and write caching are
enabled. If you specify a drive letter followed by a minus (-), read and write
caching are disabled.
/C Write all cached information from memory to the hard disk. Smartdrive
writes information from memory to the hard disk at times when other disk
activity has slowed. You might use this option if you are going to turn off
your computer and want to make sure all cached information has been written to
the hard disk."
and at the end of the section…
"CAUTION- Check that Smartdrive has completed all write caching before you turn
off your computer. To make sure this has happened, type SMARTDRV /C at the
ms-dos prompt. After all disk activity has stopped, you can safely turn off
your computer."
Thats all I know. This manual is fairly new but is pre-DOS 6.0. Maybe
yours is an older one (?). I guess the facts will vary quite a bit depending on
the exact version one is talking about, which makes it difficult to try to give
advice about it unless everybody involved states the exact version number of
smartdrive they're running (apparently the DOS version that they got it with is
meaningless).
Well, I have to say I don't want to even think about smartdrive anymore, so on
another subject… After hearing all the rave reviews (including yours) I
picked up a copy of INSIDE 3D STUDIO, and even though I've only scanned through
it, it looks like its got alot of useful info in it and some great tips. It
should come in real handy (even more so if only I had time to actually sit down
and read it!)
David
David,
The cautions apply to using SMARTDRV /C command which is not the same as the
original SMARTDRV. The old SMARTDRV and SMARTDRV /F, both the defaults appear
to be the same from my reading of the manuals. The main difference being that
you have to disable the old SMARTDRV if you don't want to use it and with the
new Version you have to enable it if you want to use it. 🙁
I think from this you can deduce that the Default is fairly safe but the
increased performance with SMARTDRV /C runs the risk of losing data if not used
properly or the system locks up.
The caveat is, if you're going to use a cache know the risks. So its probably
wise that Microsoft by default has disabled "write back" as the default.
Actually a fast processor, fast display card, fast hard disk and a lot of RAM
is the ideal anyway.
Your manuals appear to have the same contents as Ver 6.2 FWIW. I have DOS 5
with the hologram on the spine, which was the manual for DOS 5 and wasn't
upgraded. I think there's some confusion about /F and /C but I'm sure by now
you've probably figured that out.
I'd agree about the versions of smartdrv making it confusing, which is why I
agreed with Gus that the best idea was to disable the cache in the first place.
It may or may not be the problem but at least that eliminates the potential.
Then you can go back if you're interested and customize it to your liking.
Caches can be very tricky but most literature hasn't gotten into the potential
problems. And Microsoft hasn't given good instruction on proper use until
recently. And even then its not very clear.
>> INSIDE 3D STUDIO .. It should come in real handy (even more so if only I had
time to actually sit down and read it!)
I felt exactly the same way, but actually it hasn't been a problem because the
way its organised you can just flip through it and something captures your eye
and what ever it is is usually just a couple of pages which you can get through
fast as a result. I think the trick is to keep it on the desk, and just pick it
and fan through it. That's what I've been doing and I've found it interesting
in the approach and ideas. Its a handy book.
So I guess will bury SMARTDRV, eh? 🙂
-JE