Can someone double check my settings for me as not mined many SHA3 coins. I have 2 x R9 280x cards. I am mining and showing speeds of around 275MH on each card when running the batch file.

The settings I am using are below.

cgminer.exe --keccak -o stratum+tcp://meth-stratum.hashfever.com:3277 -u robertson2013.worker1 -p password --lookup-gap 2 --thread-concurrency 8192 -g 2 -I 13 -w 256 --gpu-engine 1070 --gpu-memclock 1500


On the pool I only show around 146MH is this normal or is there any tweaks I can make to the above?