My robust broadcom wifi card interferes with my graphic card
I advise you to reduce the card signal level. This won't reduce the speed which is only related to the frequency of the carrier wave and the signal / noise ratio.

This will increase the overall signal / noise ratio of all the hardware using the bandwidth around the GHz (1 - 10 GHz). Net result: the interference should stop below a level to experimentally find. Then the network throughput will be better, but its scope (in meters reached) will be shorter. Most probably you will shrink your network radius from 100 m down to 25 m. You will also lower the quantity of micro-wave heating your eyes and your brain (every thing which is containing a lot of water).