How to save about 500GB of data in a database?

I want to save the bitcoin data and build a Bitcoin Indexer. While saving the data, the write speed becomes slower more and more. The size of all data is about 500GB and when it arrives to about 20GB, the speed is extremely slow. Notice that I have 4 tables and each table has some indexes and I’ve tried both MongoDB and MySQL. What would be a proper way for this?