I don't know if it's faster than opening a pipe from gunzip like you do, but any time I need to read .gz files I use Compress::Zlib. Since it's an actual module, it may be faster than opening the pipe (especially if called repeatedly) since that probably involves spawning a new process. Compress::Zlib is easy to use and lets you read directly from the gzipped files. Here's a simple gzcat example taken directly from the Compress::Zlib docs:

    use strict ;
    use warnings ;

    use Compress::Zlib ;    

    die "Usage: gzcat file...\n"
        unless @ARGV ;
    
    my $file ;    
    foreach $file (@ARGV) {
        my $buffer ;
    
        my $gz = gzopen($file, "rb") 
             or die "Cannot open $file: $gzerrno\n" ;

        print $buffer while $gz->gzread($buffer) > 0 ;
   
        die "Error reading from $file: $gzerrno" . ($gzerrno+0) . "\n"
+ 
            if $gzerrno != Z_STREAM_END ;

        $gz->gzclose() ;
    }
[download]