Originally posted by vjs
For example, alot of computer have either 256k or 512k L1 cache
L2 cache, I guess...

However,
48.5 1.5 30k 285k .793% would fit into a 256K cache
I don't have insights into the factoring algorithm and its memory needs, but I don't think that you can equal B2 value (in digits) and L2 cache size (in Bits).
For Step2, you need a lot of RAM - 256MB is good, 512 MB maybe even a bit better...