Mining difficulty slowing down over the next 3 months?

[davejh]

I think I have an idea and have observed on my own rigs over the last few months but what effect does diff have exactly on payout. If diff increases by 20% is it exactly 20% less payout? or is it proportional?
My own observations, be they anecdotal at best, seem to show diff in crease doesn't have as high an effect as it first seems.

When the difficulty increases by 20% then your hashing capacity is now effectively 100/120 of what it was. You'll see 83.3% of what you did before.

[DrG]

I think I have an idea and have observed on my own rigs over the last few months but what effect does diff have exactly on payout. If diff increases by 20% is it exactly 20% less payout? or is it proportional?
My own observations, be they anecdotal at best, seem to show diff in crease doesn't have as high an effect as it first seems.

As noted above simply take (old dif) / (new dif) to see how much less you will earn.  You shouldn't look at day to day earnings, however, because those can swing off from the expected averages quite a bit based on pool luck.  Over the 2016 block interval it should be close assuming the pool doesn't have a tremendous variability during that time.