I think you probably bumped the frequency too high (where your PSU cannot supply enough power/chip overheats).
According to Roxie (owner of Rockminer) you need to set your frequency to 320mhz to acheive the correct hashrate. Once you do this, you need to run the R-BOX for at least 2 hours to "let the stats stabilize" (I don't know why exactly, but it advises this in the official thread).
Good luck!
Topic: Rockminer R box keeps dropping hashrate :/ (Read 1272 times)
I got the R box about a week ago. I never got the 100-110 ghs I was supposed to get until I changed the frequency to 330. Everything was fine until I noticed the hashrate had dropped from 108 to 80. Then my sister came and used the computer and quit cgminer by accident. Now I am only getting 80 ghs maximum but it eventually drops to 40 ghs and won't go up that much :/ I tried on my mac on macminer and it is still pretty much the same... any suggestions ?
Jump to: