I'm also seeing some strange fluctuations - I have one system with two 7850s getting roughly the same hashrate on the worker as a second system with only one 7850 on a worker. I feel like I'm asking something that was probably already answered, but why does the value reported on the website vary so much from what my miner says? The website says anything from 100 to 700 Khash/sec for a single 7850 when the miner on my pc says 260 Khash/sec right now.
What settings are you using for your 7850. I've seen to be fluctuating between 120kh/s to 300kh/s depending on settings.
I'm using GUIMiner-scrypt right now with the low usage 7850 preset with slightly tweaked intensity - the settings are currently:
Thread concurrency: 8192, Worksize: 256, Vectors: 1, Intensity: 13, GPU threads: 2
I'm not sure if these are the right settings to even be using for this - I just tweaked the intensity since I was getting significantly lower hash rates both on the pool and miner for anything below 13.
Right now I really have no idea if I'm doing this right - I just started mining with my cards since I had some free time and have no experience mining scrypt coins.
Edit: I don't know if it matters but I have a few of these 7850s -
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161406