Excuse me while I whip this out:

#code that populates hashes here

while( my ($oid, $perf) = each %table_match ) {
   if ( $get_snmp{$oid} == $get_perf{$perf} ) {
      print "OID: $oid and PERF: $perf are equal in value.";  
      print "The value is $get_snmp{$oid}.\n";
   }
   else {
      print "OID: $oid has value $get_snmp{$value} "
      print "while PERF: $perf has value $get_perf{$perf}."
      print "  The two are not equal.\n";
   }
}
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Whether or not you use references shouldn't really effect the performance. Update:Fixed typo as per below.