Better Implementation (Score 3, Interesting)

As mentioned, DJB's primegen is much faster. Even his Sieve of Eratosthenes implementation will do the primes up to a billion in 1.38 seconds on a 2.4 GHz P4, which is roughly 100x faster than this guy's "all primes below 100 million in less than 13 seconds" (although he doesn't specify on what machine). There's no reason to be using huge memory "pages," you can sieve up to N with any size interval you want (like say, the size of your L1 d-cache) using only Sqrt(N) memory for the primes up to Sqrt(N).