We have an application where we needed to parse 100+ meg log files in real time for various strings and I had the same problem. I found that I was able to get a significant speed boost by offloading the string matching aspect to unix grep and piping the output into perl. It cut the time down from several minutes to under 30 seconds. 
    $cmd = qq|grep '$string' access.log|; 
    open(LOG,"$cmd|");
    while (<LOG>) {

    # etc..

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In reply to Re: Searching large files before browser timeout by Davious
in thread Searching large files before browser timeout by aijin

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