HVC. Somehow, 1GH's HVC pool have fixed diff and it gives higher hash rates. Im just wondering if you are able to implement it.
1GH fixed its HVC pool diff at 0.24999619
not sure about how the value affects hash rate though...
I opened 60475 port as fixed diff 0.24999619
Connect to 60475 port if your miner rig is enough to hash upto this diff.