No, its automatically controlled usually, if you use a program like Amd's catalystengine or Rivatuner for example you can alther the Gpu's fanspeed, but Gpu's do run hotter than Cpu's, a cpu at 90'C is a worry, not so with a Gpu
I prefer coretemp personally as I can set it up on my taskbar to monitor at a glance without having to open it up
but if you want to whack your gpu fan/fans up, use the Catalyst control centre/engine, thats the easiest way,
*Edit, good call geek for Gpu-z
Moto