First and foremost, the amount of RAM you have in your system is dependent on the number of programs you run simultaneously. That is to say, the more programs, the more RAM you'll likely need. Though keep in mind some programs use very little RAM, while others can take much more.
To find out how much RAM you realistically need, begin working on your Android tv box as you normally would. Open your normal programs and begin your normal tasks. Once you're running as normal, open Setting Manager, then select the "Performance" tab and locate the "Memory" subsection. This will tell you how much of your total amount of RAM you're currently using. My rule of thumb is if you're using less than 75%, you likely don't need an upgrade in RAM, if you're consistently above 75% you should consider upgrading your RAM.
The newer your Android tv box system, the more likely you need 4GB of RAM. Android 6.0 and Android 7.0 ran pretty well in 1GB and 2GB of RAM, respectively. Android 8.1 and 9.0 need more (though the requirements plateaued somewhat) than 2GB realistically. They do pretty well with 4GB.
The difference between those two amounts specifically is actually a pretty big difference. For most modern games 2GB of RAM isn't nearly enough, especially if you go anywhere above medium settings.
Having 4GB will definitely help with frames.
1. If your Android tv box is 2GB RAM, or less than 2GBRAM, So, it is recommended not to upgrade your tv box firmware. Using Android 7.0 is a good match. If your tv box is 4GB memory, you can update it to The latest Android 9.0 firmware.
2. If you often use Android tv box to play games, then it is recommended to buy 4+32GB or 4+64GB Android tv box, such as model H96 max x2, H96 max+ and H96 max rk3318.
3. The average elderly watch TV, there is no other functional requirements, 2+16GB is enough to use, the current stable models are H96 mini, H96 max+