Restore original benchmark size and number of repeats.

bench-sieve.txt

@@ -2,8 +2,8 @@
 // 178589010 nodes evaluated in 2.129754 seconds = 83854290 nodes/sec
 // 178589010 nodes evaluated in 2.126711 seconds = 83974273 nodes/sec
 
-numbers = 819200; // 1028 primes
-repeats = 10;
+numbers = 8192; // 1028 primes
+repeats = 200;
 
 count = 0;