What make and model is that 2 TB storage drive? How is it connected?
In general, I doubt that there is much you can do.
You may regain some speed if the SSD is used as a dedicated target drive for specific files and applications. You would just need to configure the 120 GB SSD as the default destination drive for those applications and/or file types.
And bear in mind that connecting the SSD may require some SATA rearrangements based on the motherboard' design and requirements to support the Samsung 970.
I am now using those smaller SSD's just for general backups via a temporary USB connection. The SSD's are easy to transport and store. External drive cases/enclosures are becoming very inexpensive if you even want one. Do not buy the low end cheaper products. At least get an enclosure that truly provides some physical protection.
However, if the question is performance in general - more RAM may help. Still the 2 TB is likely going to be the limiting component.