Even better if it results in some passive income. One idea I had is to use the 4 nodes to mine bitcoin. Supposedly, you can use CPU as well as GPU to mine but I'm still investigating.
If you want a more philanthropic option, see https://en.wikipedia.org/wiki/Berkeley_Open_Infrastructure_f...
You can crunch numbers for astronomy research https://en.wikipedia.org/wiki/List_of_distributed_computing_...