From: Joseph McDonald <joe@...>
Date: 2002-03-08T00:58:56+09:00
Subject: Re: file reading impossibly slow?


>>>In 1.7, IO#read is much faster than IO#gets.  Your example run
>>>in 101sec, 49sec with read(65), and 19sec with read(65000).

RJ>> On over 300 megs of file? It takes Windows six minutes to copy it. What are you
RJ>> using for hardware / software?

JM> But you're only reading, not writing.  19 seconds is in the realm of
JM> possibility.  Here is an example:

JM> ~$ ls -l 300megs.txt
JM> -rw-r--r--  1 joe  joe  300000000 Mar  7 07:38 300megs.txt
JM> ~$ time cat 300megs.txt > /dev/null

JM> real    0m3.733s
JM> user    0m0.211s
JM> sys     0m2.931s

JM> 3.7 seconds to read the file.  This is on a pentium 500 running
JM> FreeBSD with 2 scsi disks striped.  The system is fairly busy serving
JM> up web and crunching data.

Oh I forgot to time a copy:
~$ time cp 300megs.txt 300megs.txt.copy

real    0m34.761s
user    0m0.015s
sys     0m5.588s

so it's about 9 times faster than your 6 minutes, so perhaps you could
multiply my 3.7 seconds read time by 9 to get 33 seconds "theoretical
max" read time for your setup?  Or just take it as another
datapoint... :-)

-joe