i can confirm lowering the core indeed give some 20 to 30 odd KHZ per card (for me), and adding the --shaders xxxx option gives a few more!

https://lh6.googleusercontent.com/-Qol4_sjSK1s/UvzOaA5mabI/AAAAAAAAGmE/Z1FEBv28qzE/w715-h434-no/vert2.jpg

TC: 8192
shaders: 2048
I 13
G 2
Core/Mem: 1030/1500

again plz igonre the GPU 1 (iGPU)