Count primes $ perl algorithm3.pl 4294967296 Prime numbers : 203280221 Compute time : 0.623 sec $ perl primesieve.pl 4294967296 Prime numbers : 203280221 Compute time : 0.252 sec $ perl primeutil.pl 4294967296 Prime numbers : 203280221 Compute time : 0.210 sec Sum of primes $ perl algorithm3.pl 4294967296 --sum Sum of primes : 425649736193687430 Compute time : 1.090 sec $ perl primesieve.pl 4294967296 --sum Sum of primes : 425649736193687430 Compute time : 0.367 sec $ perl primeutil.pl 4294967296 --sum Sum of primes : 425649736193687430 Compute time : 0.768 sec Print primes ( outputs 2 GB containing 2032802221 prime numbers ) $ perl algorithm3.pl 4294967296 --print >/dev/null Compute time : 2.086 sec $ perl primesieve.pl 4294967296 --print >/dev/null Compute time : 1.397 sec $ perl primeutil.pl 4294967296 --print >/dev/null Compute time : 1.925 sec