Um...

    Bytes_read => 40960,
    BlockSize  => 40960,
[download]

that's 40kb, not 4kb: 4096. And 4096 may not be the best setting on all systems. Ie. yours. You'd need to try various different settings.

You should also perform your testing with a considerably larger file than that 2kb README.

Also, try using Net::FTP itself rather than Net::FTP::Robust & Net::FTP::Throttle. Whilst they may be valuable, they are almost certainly going to slow things down somewhat.

But mostly, try turning off Debug--that will also slow things down.

I used a modified version of your script to grab the same 5MB file using Net::FTP and wget, and both achieve remarkably similar throughputs, with Net::FTP actually beating wget when I used a 4096 byte blocksize:

c:\test>wget --passive-ftp ftp://ftp.perl.org/pub/CPAN/ports/win32/Sta
+ndard/x86/perl-5.6.0.tar.gz
--04:26:04--  ftp://ftp.perl.org/pub/CPAN/ports/win32/Standard/x86/per
+l-5.6.0.tar.gz
           => `perl-5.6.0.tar.gz.1'
Resolving ftp.perl.org... done.
Connecting to ftp.perl.org[193.136.239.1]:21... connected.
Logging in as anonymous ... Logged in!
==> SYST ... done.    ==> PWD ... done.
==> TYPE I ... done.  ==> CWD /pub/CPAN/ports/win32/Standard/x86 ... d
+one.
==> PASV ... done.    ==> RETR perl-5.6.0.tar.gz ... done.
Length: 5,443,601 (unauthoritative)

100%[====================================>] 5,443,601    278.97K/s    
+ETA 00:00

04:26:24 (278.97 KB/s) - `perl-5.6.0.tar.gz.1' saved [5443601]


c:\test>ftp-get -SIZE=81920
Got 5443601 bytes at 273685.318/second

c:\test>ftp-get -SIZE=40960
Got 5443601 bytes at 286686.382/second

c:\test>ftp-get -SIZE=4096
Got 5443601 bytes at 300668.379/second
[download]

Hardly definitive, but worth a few trials.

The code I used:

#!/usr/bin/perl
use strict;
use warnings;
use Time::HiRes qw[ time ];
use Net::FTP; ##::Robust;
##use Net::FTP::Throttle;
##use Log::Report;

use constant HOST => 'ftp.perl.org';
use constant DIR  => '/pub/CPAN/ports/win32/Standard/x86';
use constant FILE => 'perl-5.6.0.tar.gz';

our $SIZE ||= 4096;

my $start = time;

my $ftp = Net::FTP->new(
    HOST,
    #Debug => 1,
    Passive => 1,
    Timeout => 1,
    Bytes_read => $SIZE,
    BlockSize  => $SIZE,
#    MegabitsPerSecond => 2
) or die "Couldn't connect: $@\n";

$ftp->login('anonymous');
$ftp->cwd(DIR);
$ftp->binary;
$ftp->get(FILE);
my $size = $ftp->size(FILE);
$ftp->quit;

printf "Got %d bytes at %.3f/second\n",
    $size, $size / ( time() - $start );
[download]