I wouldn't use sieve depth and factor worth.
I'd simply specify the B1 and B2 values.

Since it will be a while until we get to 14M I would suggest you use.

B1=100k to 120k with a b2=b1x12 to b2=b1x14 depending on how much memory you have.

in other words,

minimum
B1=100000 b2=1200000

maximum
B1=120000 b2=1700000

What CPU memory and amount of memory do you have?