If you put your data items in to a normal array, and form the linked list by prefixing the index of the next item to the front (or stick it on the end), then your worst case of 2e6 x 40b and 120e3 x 338, only requires 1/4GB.

Hide the mechanics behind a suitable OO interface and you can hand out instance handles that are just blessed integers.

#! perl -slw
use strict;

our $BIG ||= 60e3;
our $LIL ||=  1e6;

my( @biguns, @liluns );

push @biguns, pack 'NA338', scalar @biguns, 'X' x 338 for 1 .. $BIG;
push @liluns, pack 'NA40',  scalar @liluns, 'Y' x  40 for 1 .. $LIL;

system qq[tasklist /fi "pid eq $$"];
<STDIN>;

__END__
C:\test>618996 -BIG=60e3 -LIL=1e6

Image Name                   PID Session Name     Session#    Mem Usag
+e
========================= ====== ================ ======== ===========
+=
perl.exe                    2340                         0    123,984 
+K


C:\test>618996 -BIG=120e3 -LIL=2e6

Image Name                   PID Session Name     Session#    Mem Usag
+e
========================= ====== ================ ======== ===========
+=
perl.exe                    2656                         0    246,096 
+K
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