AB

#!/usr/bin/env perl6

say "begin " ~ now;

my $b=0; 
my @a; 
for ^10_000 {
    @a[$_]="1,2".split(',');            # Version A
#    @a[$_]="1,2".split(rx/\,/);        # Version B
}

say "array built " ~ now; 

for ^10_000 { 
    $b += @a[$_][1] ;
    say "{now} $b" if $_ %% 100;
}

say "done " ~ now; 

Version A

➤ ./foo
begin Instant:1396990636.693208
array built Instant:1396990640.108674
Instant:1396990640.206750 2
Instant:1396990649.143116 202
Instant:1396990658.176402 402
Instant:1396990667.219585 602
Instant:1396990676.421648 802
Instant:1396990685.607861 1002
^C
[ I killed it because it was taking too long ]

Version B

➤ ./foo
begin Instant:1396990577.881330
array built Instant:1396990593.909020
Instant:1396990593.918197 2
Instant:1396990594.172442 202
Instant:1396990594.330368 402
Instant:1396990594.487493 602
Instant:1396990594.645900 802
Instant:1396990594.805878 1002
Instant:1396990594.965995 1202
Instant:1396990595.125706 1402
Instant:1396990595.283551 1602
Instant:1396990595.440816 1802
Instant:1396990595.599652 2002
Instant:1396990595.758766 2202
Instant:1396990595.916310 2402
Instant:1396990596.073807 2602
Instant:1396990596.325744 2802
Instant:1396990596.481020 3002
Instant:1396990596.636637 3202
Instant:1396990596.791717 3402
Instant:1396990596.947357 3602
Instant:1396990597.102455 3802
Instant:1396990597.259007 4002
Instant:1396990597.415904 4202
Instant:1396990597.572744 4402
Instant:1396990597.730328 4602
Instant:1396990597.887457 4802
Instant:1396990598.044537 5002
Instant:1396990598.293091 5202
Instant:1396990598.447476 5402
Instant:1396990598.602488 5602
Instant:1396990598.758292 5802
Instant:1396990598.913991 6002
Instant:1396990599.071256 6202
Instant:1396990599.224728 6402
Instant:1396990599.378616 6602
Instant:1396990599.534831 6802
Instant:1396990599.689569 7002
Instant:1396990599.844318 7202
Instant:1396990599.998756 7402
Instant:1396990600.151556 7602
Instant:1396990600.390585 7802
Instant:1396990600.543136 8002
Instant:1396990600.697963 8202
Instant:1396990600.851150 8402
Instant:1396990601.004038 8602
Instant:1396990601.156162 8802
Instant:1396990601.308026 9002
Instant:1396990601.459248 9202
Instant:1396990601.611765 9402
Instant:1396990601.764519 9602
Instant:1396990601.915923 9802
Instant:1396990602.068787 10002
Instant:1396990602.307730 10202
Instant:1396990602.462508 10402
Instant:1396990602.611987 10602
Instant:1396990602.762498 10802
Instant:1396990602.911911 11002
Instant:1396990603.061824 11202
Instant:1396990603.209843 11402
Instant:1396990603.359524 11602
Instant:1396990603.509275 11802
Instant:1396990603.657756 12002
Instant:1396990603.806094 12202
Instant:1396990603.955789 12402
Instant:1396990604.104698 12602
Instant:1396990604.328455 12802
Instant:1396990604.473469 13002
Instant:1396990604.619183 13202
Instant:1396990604.767621 13402
Instant:1396990604.915789 13602
Instant:1396990605.062546 13802
Instant:1396990605.208417 14002
Instant:1396990605.356207 14202
Instant:1396990605.505910 14402
Instant:1396990605.654203 14602
Instant:1396990605.803145 14802
Instant:1396990605.952370 15002
Instant:1396990606.175698 15202
Instant:1396990606.320280 15402
Instant:1396990606.465177 15602
Instant:1396990606.609418 15802
Instant:1396990606.755389 16002
Instant:1396990606.900542 16202
Instant:1396990607.045732 16402
Instant:1396990607.190252 16602
Instant:1396990607.334388 16802
Instant:1396990607.477455 17002
Instant:1396990607.620898 17202
Instant:1396990607.765557 17402
Instant:1396990607.910214 17602
Instant:1396990608.120012 17802
Instant:1396990608.260026 18002
Instant:1396990608.400371 18202
Instant:1396990608.540580 18402
Instant:1396990608.682816 18602
Instant:1396990608.824286 18802
Instant:1396990608.965953 19002
Instant:1396990609.106599 19202
Instant:1396990609.247370 19402
Instant:1396990609.387488 19602
Instant:1396990609.528049 19802
done Instant:1396990609.673621