so you think this 0.0039 btc is good earning in 24H ?
I would say it's based on your speed. How you mentioned it dropping sometimes to 380, I would say yes that is good for it dropping so much.
If it was getting a solid 440 GHs I would think a little more is better. But It all depends on the sped your running, and amount of work that is accepted.
i going to will buy s5 but any problem will be ? i will have similar problem (ghs) ?
which will buy s5 if s3 ?
Honestly I think you would be best off figuring out the S3 before expanding much. It seems you are still having problems such as speed, etc.
I highly still suggest contacting bitmain support as the offered. Your problems are just stretching into multiple boards looking like spam on a level. If you work with bitmain support you will be better off.