Pretty much every flagship smartphone in 2017 come with 6 GB of RAM, except for Samsung's Galaxy S series. Many fans expected to see at least 6 GB of RAM, but the Galaxy S8 phones only arrived with 4 GB, with 6 GB being available only in select countries.
The bad news is that the Galaxy S9 won't bring some drastic changes to the table. In fact, the new lineup will still have a 4 GB variant according to Geekbench and previous reports suggesting the Galaxy S9 and S9+ will be stuck on 4GB RAM were accurate. Hopefully the 6 GB variant will have wider availability.