Weird. On two rigs (1 and 2) I avg about 1,300 kh/s but on the rig (3) with issues it starts off at about 800 kh/s but drops to about 200 kh/s.
On rig 3, with issues, I have an old AMD tri core but on rig 1 and 2 I have an AMD 1100t and 8350. So maybe the cpu is causing problems. But on rig 1 and 2 I get 90-97% gpu usage but rig 3, with issues, the gpu usage only gets to about 40% but drops to under 10%.
So I don't thinmk it is the nvminer but wanted to compare with ccminer. I was mining core coin which ends real soon so I will try another x15 coin late tonight when I get home from work.
Also possible it's the GPU. Could you try and switch GPUs between machines to see if the problem follows the GPU or the CPU?
Carlo
Each machine has 5 750ti's on powered USB risers. This one has 5 MSI factory overclocked. The one with no problems are Evga super clock. The MSI (problem computer) are clocked higher.
It might be easier to change out cpu's.