AXDRW%ALASKA.BITNET@cunyvm.cuny.edu (Don R. Withey) (10/20/88)
Well someone asked on the net about transfer speed for the FFS, it got me
to wonder about how fast my system might go under the FFS. I have the
following configuration: Amiga 2000, A2052 2meg memory board, A2090A hard
disk controller, Seagate ST277N hard disk. I wrote a simple program to
allocate a buffer of some size and then write it a number of times to
a file, and then read it back into the same buffer. I was fairly amazed
at the speeds that I was able to get. The results shown below were generated
with an iteration count of 10. Just for grins I provided the program also.
It is writtin in Lattice C 4.0 (I can't wait until I get my hands on 5.0 ;-)
Your milage may vary, the average seek time for a ST277N is 40ms by the
way.
Don
block read write
size k/sec k/sec
--------------------------------------
32k 320.0 216.22
64k 383.23 261.22
128k 414.24 287.64
256k 414.91 304.76
512k 425.25 316.44
----#cut here#--------------------------#cut here#----
#include <stdio.h>
#include <dos.h>
#include <exec/memory.h>
#include <proto/dos.h>
#include <proto/exec.h>
void main()
{
long f;
char *buff, t1[8], t2[8];
long time1, time2, i, iter, size;
double ksec;
printf("Enter block size in Kbytes->"); /* get buffer size for io */
scanf("%ld\n", &size);
size = size * 1024;
printf("Enter number of iterations ->"); /* get number of iterations */
scanf("%ld\n", &iter); /* to use buffer per operation */
printf("Block size, interations = %ld, %ld\n", size, iter);
buff = (char *)AllocMem(size, MEMF_CLEAR);
if (buff == 0) { /* alloc failed so exit */
printf("Not enough contigious memory; block size = %ld\n", size);
exit();
}
f = Open("test.file", MODE_NEWFILE);
getclk(t1); /* get system time */
for (i = 0; i < iter; i++)
Write(f, buff, size);
getclk(t2);
/* the getclk call returns an char array[8], where array[5] is minutes,
array[6] is seconds, and array[7] is hundredths of seconds */
time1 = t1[5] * 6000 + t1[6] * 100 + t1[7];
time2 = t2[5] * 6000 + t2[6] * 100 + t2[7];
ksec = (double)(((double)(size * iter) / (double)(time2 - time1))
* 100.0) / 1024.0; /* convert elapsed time to k/second */
printf("elapsed time for write = %ld, K/sec = %10.4f\n",
(time2 - time1), ksec);
Close(f);
Delay(100); /* give file system time to settle before next test */
/* didn't know if I needed this, but just in case */
f = Open("test.file", MODE_OLDFILE);
getclk(t1);
for (i = 0; i < iter; i++)
Read(f, buff, size);
getclk(t2);
time1 = t1[5] * 6000 + t1[6] * 100 + t1[7];
time2 = t2[5] * 6000 + t2[6] * 100 + t2[7];
ksec = (double)(((double)(size * iter) / (double)(time2 - time1))
* 100.0) / 1024.0; /* convert elapsed time to k/second */
printf("elapsed time for read = %ld, K/sec = %10.4f\n",
(time2 - time1), ksec);
Close(f);
DeleteFile("test.file"); /* get rid of the temp file */
FreeMem(buff, size);
}
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Don R Withey BITNET: AXDRW@ALASKA.BITNET
University of Alaska BIX: dwithey
3211 U.A.A. Drive
Anchorage, Alaska 99508
907-786-1074 (work) 907-277-9063 (home) 907-274-6378 (other home)
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Any expressed opinion is my own and in no way represent those of my employer,
the University of Alaska.