Primesieve : Very Fast Prime Number Calculator

We have previously posted about Prime95 which is an excellent prime number calculator. It can be used to stress test your computer and find out of the computer is poorly built. Now there is another similar application called Primesieve which is open-source and can calculate prime numbers very fast without using much of your system resources. While Primesieve can calculate smaller primer numbers in microseconds, it also takes a few extra seconds when calculating very large numbers in ranges like 1 × 10²³.

Primesieve is a command line application and does not offer any GUI. The program comes with a –help command line switch using which anyone can understand the basics of how to use this program. Basically, if you want to calculate prime numbers up to a number then you have to give that number as the parameter. For example, if you give a command primesieve 1e10 then it will calculate prime numbers up to 1 × 10¹º.


But it does not print all the calculated prime number values by default. In order to make it print all the prime number, we have to append –print in the end of the command. For example, if you want to print prime numbers between 1 and 1000, then the command would be primesieve 1000 –print.


The program can also print twin prime numbers and triplets and so on using the same  –print switch. For example, if you want to print twin prime numbers between 1 and 100, then primesieve 100 –print=2  will be the command. For printing triplets, we have to change –print=2 to –print=3 and so on.


There are many features and options offered by this small application. One of them is to run tests on your system. For running the tests, you can give the command primesieve –test. It calculates higher order prime numbers in many different ways. The CPU might become overwhelmed by this test but it never causes any stability problem.

You can download Primesieve from