Review Adata XPG Gammix S50 Lite M.2 NVMe SSD Review: Low-cost PCIe Gen4 Goodness

I know what you mean, but the Storage Review article says that this drive is slow even in comparison with PCIe3 drives.

I am wondering if it is because the Tom's review was for the 2 GB version, whereas the Storage Review Article is for the 1 GB version, and the 1 GB version of the drive is slower? It does appear to have a lower specification in some areas.
 
Maybe it also relates to their testing methodology. Storage review say that they completely fill the drive then partition 5% to test on. Perhaps that has an unexpected effect?
 
It looks like all brands have some controllers to choose from and you will never know which one they are using. tha'ts why they never say the exact controller they are using. Just general speed performance. They don't want to be attached to any supplier/brand.