Want to add RAM do I need to add CPU

Hi

Have a Dell RX730 at a remote site (so can't check at server) and I need to add RAM to it.   I can see it has 2x Intel Xeon e5-2680 v3 CPUs with 512GB of RAM.   RAM is made up of 16x32GB modules leaving 8 free.  

Easiest solution would be to populate the remaining slots with 32GB modules giving extra 256GB which would be fine, but would I need to add an additional CPU to see and use this RAM.   

I guess what am I asking is does each CPU manage 8 memory slots on the board?

Thanks