This does not sound like a PSU problem. What OS and patch version are you running? Also, what are your drive settings in the advanced settings of the Power & Sleep Configuration?
To address your question, indeed, it is feasible. NVMe drives and PCIe components like your graphics card often share the same bandwidth pipeline, bus. However, it's important to note that the performance metrics you've mentioned aren't concerning. A...
Here are a few questions that can be answered using Samsung Magician:- Is the NVMe firmware up-to-date- Is trim enabled under performance optimization - Is Over-provisioning enabled- do you pass a full diagnostic scanThe results look pretty good, exc...