Agent Starch

So the warranty on my Asus Zenbook UX433 expired yesterday so I did what I love to do. I took it apart to have a look inside Everything was expected until I got to the Storage Drive. It is a 256GB Western Digital NVMe SSD with a B+M Key Edge Connector. Sounds simple enough right? It is until you look at the actual connector on the Motherboard. The Motherboard is a M Key Connector... Now obviously it still works so it isn't a bad thing. But why did Asus mix the different connectors? Is there some sort of advantage to using the M Key Connector with a B+M Key Drive?

So... I have been running my main computer on a Intel Core i5-6500. Since I got it, the CPU has performed well as it was new despite the fact it was released in Q3 of 2015. However, recently, my PC has been running super slow to do anything. It takes a long time to boot and a long time to actually finish booting. Yes, I am only running a SSHD which isn't very fast but my computer has got slower over time. I am wondering if it is due to the CPU. Is the i5-6500 too old now and if so, should I invest in a 7th generation processor? Or is it most likely my slow storage?