What is the performance difference between 3400G & 3300X if paired with 1650S or 1660S?

The pc will be used for gaming and media consumption only. But currently don't have the budget to buy the gpu. So I have to buy the cpu+mobo now and will buy the gpu at the end of next month.

My GPU of choice is a 1650 Super or a 1660 Super.

Now, as I need a pc urgently, I decided to take 3400G. But I'm confused. Should I buy Ryzen 5 3400G or Ryzen 3 3300X? In case of 3300X (or 3500X), I will be using my 10 year old gpu for display, Nvidia GT520 (will it work though?).

I know Ryzen 3 3300X is lot better than 3400G, but all the tests I found are done on 2080Ti. As that won't be my case and I won't be hitting those high numbers, how much performance difference can I expect using a 1650S or 1660S with 3400G and 3300X? If it’s not huge, I might go with 3400G, cause at least the iGPU can run some of the online games for now.