Sieving does not need primetest reserve.
If we sieve a large range, I recommen also to include the low n part (for example (3 to 20G). The sieving of a 20G range speed is almost the same as 5G.
Without knowing your efforts I tried also a bit sieving on 3  10G up to 10T with a speed of 80M/s or 6.5T/day (P4 3.4GHz).
At 10T, there are ~4.6M candidates left which is about 85M text file or 16.5MByte Zipped. Removing 3 candidtes /s at 10T.
when sieving 20G reching 50T (1 Week sieving), such a file (twice as big) could be distributed, sieved more and then merged again.
I people run prime tests on a range of 100M or less, it already makes more sense to take the presieved ranges insted of own sieving.
