The GRT code you are using packs the numbers as 32 bits which is not a good thing to do for file sizes nowadays!

Anyway, I have added code to benchmark the sorting algorithms provided by Sort::Key and Sort::Key::Radix... 


...

use Sort::Key::Radix;
my $skr = sub
    {
        my @sortedKeys = Sort::Key::Radix::nkeysort { $hash{$_}{Size} 
+} keys %hash
    };

use Sort::Key;
my $sk = sub
    {
        my @sortedKeys = Sort::Key::nkeysort { $hash{$_}{Size} } keys 
+%hash
    };



cmpthese(
   -5,
   {
       ClassicGRT => $rcClassicGRT,
       ClassicST  => $rcClassicST,
       Jethro     => $rcJethro,
       Simple     => $rcSimple,
       SK         => $sk,
       SKR        => $skr
   } );

[download]
and these are the results: 
             Rate    Simple ClassicST ClassicGRT    Jethro         SK 
+       SKR
Simple     3.08/s        --      -45%       -69%      -70%       -78% 
+      -80%
ClassicST  5.64/s       83%        --       -42%      -45%       -60% 
+      -63%
ClassicGRT 9.79/s      218%       74%         --       -5%       -31% 
+      -36%
Jethro     10.3/s      234%       83%         5%        --       -27% 
+      -32%
SK         14.1/s      359%      151%        44%       37%         -- 
+       -7%
SKR        15.2/s      394%      170%        55%       48%         8% 
+        --

[download]

In reply to Re^5: What are the other option for sorting the keys of hash of hashes by salva
in thread What are the other option for sorting the keys of hash of hashes by luckypower

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