What processor architecture you're using doesnt matter as long as you are on at the very minimum a 32 bit computer running something with at least a 1.6ghz clock speed.
Roblox runs on Pentium 4's, Xeons, most things AMD, some ARM even SPARC processors if you emulate the Visual C++ environment.
View requirements here:
https://en.help.roblox.com/hc/en-us/articles/203312800-Computer-Hardware-Operating-System-Requirements