Path: utzoo!attcan!uunet!husc6!rutgers!bellcore!clyde!watmath!focsys!larry
From: larry@focsys.UUCP (Larry Williamson)
Newsgroups: comp.sys.ibm.pc
Subject: What is the fastest disk access method on AT?
Summary: I want to write a full track at a time
Keywords: disk access speed RLL fulltrack buffering
Message-ID: <211@focsys.UUCP>
Date: 24 Oct 88 14:37:04 GMT
Reply-To: larry@focsys.UUCP (Larry Williamson)
Organization: Focus Automation Systems Inc. Waterloo, Ontario.
Lines: 27


We have an application in which we write large amounts of data to
an AT disk without benefit of any file system structure or
overhead.  The disk is used only as a very large raw buffer. 

To date, we have been using DOS interrupts 25 and 26 to write and
read the disk.  We transfer 64K byte blocks with each dos call. 

This is no longer fast enough for us. We must now transfer more
data in less time, (of course :-).

We are using an adaptec RLL controller with a miniscribe drive. Core
test tells us this combination runs at over 600Kbytes/sec, yet our
tests show only 350K/s. Why this major difference? It is obvious 
that coretest is doing something different than we are. 

Any suggestions?

We are prepared to write more code to circumvent dos if necessary. 
Since the disk write and read functions that we need are extremely
simple, we don't have to provide much functionality. 

Thanks,
    larry
-- 
Larry Williamson  -- Focus Automation Systems -- Waterloo, Ontario
                       watmath!focsys!larry       (519) 746-4918