My Gridcoin.conf:
server=1
rpcuser=benhur
rpcpassword=1
rpcallowip=127.0.0.1
rpcport=9332
addnode=137.116.167.42
addnode=137.116.167.52
addnode=191.238.60.17
addnode=191.238.51.28
addnode=191.235.137.239
addnode=191.235.138.12
addnode=23.97.147.78
addnode=23.97.148.49
addnode=138.91.246.228
addnode=138.91.247.22
addnode=supernode.gridcoin.us
cpumining=true
threadlimit=1
email=XXX@XXX.com
UpdatingLeaderboard=false


It works fine for both cpu minging and gpu minging.
I'm solo mining.

My cpu is  E3 1230V2.It has 8  threads,6 threads for BOINC,1 for POB mining.