Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uwm.edu!wuarchive!m.cs.uiuc.edu!ernie!bazyar
From: bazyar@ernie (Jawaid Bazyar)
Newsgroups: comp.sys.apple2
Subject: Re: DMA?
Message-ID: <1991Apr18.203432.13718@m.cs.uiuc.edu>
Date: 18 Apr 91 20:34:32 GMT
References: <613@generic.UUCP> <1991Apr17.143801.22825@m.cs.uiuc.edu> <1991Apr17.210147.13550@nntp-server.caltech.edu>
Sender: news@m.cs.uiuc.edu (News Database (admin-Mike Schwager))
Reply-To: bazyar@cs.uiuc.edu (Jawaid Bazyar)
Organization: Mutation Testing Facility, University of Illinois
Lines: 46
Nntp-Posting-Host: ernie.cs.uiuc.edu

In article <1991Apr17.210147.13550@nntp-server.caltech.edu> toddpw@nntp-server.caltech.edu (Todd P. Whitesel) writes:
>bazyar@ernie (Jawaid Bazyar) writes:
>
>>   The RAMfast cache is what is termed as "write-through", i.e. any data
>>written to the card is immediately written through to the disk.  This is
>
>I thought the writes were supposed to be done in the background in order to
>speed things up!
>

  As has already been mentioned, I blew it. :-)

>Just copying files in finder (and this is with a Zip at 10 mhz) the Ramfast
>and quantum doesn't seem to operate as quickly as a Ramfast and a 'dumber'
>drive like a seagate or a syquest. I get this feeling that the Ramfast's
>transfer algorithm causes track-caching drives like the Quantum and Conner
>to thrash somewhat -- the fastest I seem to be able to get is 512K/sec
>(finder Verify on a 32 meg partition) and 200K/sec (finder Validate on a
>32 meg parition w/ 176k free and files of various sizes). Writes are also
>slower.

  Ack! How could it be any faster?  :-) 
  So how exactly are you timing this thing?  Are you just 'validate'ing
your drive and dividing it's size by how long it takes?

>Somebody, please tell me the 2.0 ROMs do something about this. I paid more
>money for a quantum and with a Ramfast it's actually slower than a Seagate
>I was helping somebody set up. The only other alternative is to optimize
>my filesystems but that doesn't solve the problem with write synchronization
>(I figure the RAMfast is waiting on writes as well and not taking into
>account the fact that the quantum will perform a background write of its
>own).

  I don't know. I'd like to get ahold of the 2.0 ROMs and try some tape
backup fun.  
  Is there some way to turn off the cache on the Quantum? I didn't notice
anything on mine, but then I was concentrating on hooking the puppy up
and watching it fly.
  Alternatively, you could turn off the RAMfast cache, and still have
a fast DMA card.  It might be even slower, though.

--
Jawaid Bazyar               |  "Twenty seven faces- with their eyes turned to
Senior/Computer Engineering |    the sky. I have got a camera, and an airtight
bazyar@cs.uiuc.edu          |     alibi.."
   Apple II Forever!        |  I need a job... Be priviliged to pay me! :-)