EGOLD has a minimum difficulty of 65,536 (2^16) and a maximum of 18,446,744,073,709,551,616 (2^64).
The difficulty depends on the number of units you set in the config. Currently, minting 1 EGOLD units has a difficulty of 10,485,760,000. 50 units is 524,288,000,000 etc.
So with that kind on diff, should I bother testing it with one 280x?