You missed a few alternatives. I've added them myself, and ran the benchmark again.

I must say that they perform rather poorly.

Benchmark::cmpthese(0, {
   split        => sub { @data = split(/\s+/, $line) },
   fixed_length => sub { @data = $line =~ /^.{8} {6}(.{10})(.{10})(.{1
+0})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})(.{10})$/ 
+},
   var_length   => sub { @data = $line =~ /^.{8}\s+(\S+)\s+(\S+)\s+(\S
++)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+
+(\S+)$/ },

   g            => sub { @data = $line =~ /\S+/g; },
   unpack       => sub { @data = unpack 'A8x6A10A10A10A10A10A10A10A10A
+10A10A10A10', $line }
});
[download]

Result:

                 Rate           g     unpack       split var_length fi
+xed_length
g             16954/s          --       -54%        -70%       -76%   
+      -96%
unpack        36961/s        118%         --        -35%       -47%   
+      -91%
split         56965/s        236%        54%          --       -19%   
+      -86%
var_length    70373/s        315%        90%         24%         --   
+      -83%
fixed_length 408377/s       2309%      1005%        617%       480%   
+        --
[download]

You ignore the first field, I include it... but that shouldn't matter much.