GFS does not affect your PC as a whole, it mainly affects your GPU.
The GFS app has been created to let the user choose from different power modes. This let's the users choose how much of their GPU power they wish to lend to GFS.
Games from Space uses your GPU to solve complex mathematical equations, the process can generally be described as (crypto) mining.
This utilisation "puts your GPU under stress" similar to how your GPU is "put under stress" while playing some of your favourite PC games.
Since the GFS app always kicks-in while you are idle (unless the 'always on' feature is turned on), that means your GPU is being utilised more frequently and under a higher "stress level".
Minimizing the impact on GPU
To minimise the impact and to keep your GPU happy, we've put together these few tips for beginners in this Knowledge Base article:
To power your GPU of course there is electricity consumption and with GFS this consumption is also increased to some extent.
The actual impact differs largely from user to user as you need to factor in: type of GPU, GPU wattage, GPU utilisation as well as the actual cost per kwh.
Getting an estimate
You can obtain an estimate by using online calculators or by using a watt meter. We've put together a few more tips in this Knowledge Base article: