There is nothing wrong with having multiple SSDs, except here it makes no sense. With HDDs, it was helpful to load games and programs off a separate HDD, because the response time, random read/write and sequential read/write performance of HDDs couldn't cope with everything alone. With an SSD, the response time is so slim, it is hardly measurable. I believe last time I actually saw a report about an SSD response time, it was something like 0.000027 milliseconds. Performance is up across the board. There is nothing wrong with having a second SSD if you buy one then later need more space or something, or need lots of space right off, but if the OP can pick up a decent quality high-capacity M.2 SSD right now, it is doubtful that he will need the extra space.