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very small Keyboard driver for DOS
measure your hard disk speed

RAWREAD - measure your hard disk speed

Many programs claim to measure hard disk performance.
In most cases, the source is not open and so it's difficult to tell what the program really measures.
There is the possibility to measure the disk controller speed, the raw disk speed, the file system speed, your caching software, ...

While discussing the UDMA driver, we wrote RAWREAD to measure the drivers performance.
The source is freely available, so you can see what it measures, and eventually adjust it to your own needs.

It's a very simple, yet very flexible program, allowing to measure many aspects of disk I/O.
In all cases, RAWREAD reads for about 10 seconds, and reports afterward the measured throughput.
In all cases, reads are done using a 60K buffer.
For security reasons, RAWREAD has no possibility to write.
If you want to measure write speed, you will have to modify the source code.

Download RAWREAD program and source

Measuring File Access (INT21)

This reads an existing file, using INT21 calls


Measuring DOS disk Access (INT25)

This reads from DOS a raw disk, using INT25 calls.
For WindowsNT+, the disk must be FAT.

        a:> RAWREAD C:

Measuring pure disk Access (INT13)

This reads data directly from the BIOS, using INT13 calls.
You specify the drive number starting at 0

        a:> RAWREAD 0

Additionally you can measure some parameters of the reads.

Additional options for varying parameters


ALIGN   - align read buffer on 64K boundary
ODD       - read buffer xxxx:0001
ODD2     - read buffer xxxx:0002
CACHED - same 60K data over and over again; effectively measuring controller and caching software speed.

Version Information:

10 Oct.
initial release
12 Dec 2003  corrected int21/7305 function (INT25 on FAT32) to use 1-based counting.
Noted by Steve Gibson, author of the famous  SPINRITE hard drive data recovery software


Copyright 2001-2005 tom ehlert  -- last changed on 30 Jan 14