There are many reasons for an SSD not to run at its advertised speeds. For instance, the SSD read and write speeds you find in the specs sheet are sequential. These are faster to pull off for the SSD ...
Your mini PC can do even more! Most models can be upgraded with extra RAM and a new SSD to boost performance and storage.
Another thing I highly recommend is having a spare SSD ready with an OS installation of your choice for a rainy day. Sooner ...