Crucial is what we suggest for non-Dell branded memory as Crucial is guaranteed to work in a Dell.  Dell PC's have a long history of incompatibility with some brands - some other brands work OK but there is no guarantee of working in a Dell like Crucial.     
Hello, It was suggested to me Crucial RAM  was a good price and it certainly appears to be. Is there a difference between Dell and Crucial? Should I be looking at something more specific in the tech details than just, DDR4 2666MHz I'm looking at upgrading from 16GB - 2 8GB in 2 slots to 32GB of crucial 2 16 GB sticks. Thank you.
XPS 8930, how specific do you need to be for new RAM?