Getting help with upgrading your AMD setup is really valued!
Getting help with upgrading your AMD setup is really valued!
Hello! Your current setup includes an AMD Ryzen 5 5600X with six cores, an Asus STRIX B550-F gaming graphics card, 16GB of Corsair Vengeance DDR4 memory at 3200MHz, and a Nvidia GeForce RTX 3070 with a 550W power supply. You're considering adding 64GB of RAM (four 16GB modules) and upgrading to an AMD Ryzen 9 5900X CPU. I understand you're open to spending a bit more for better performance. You'll also need to plan for a cooler upgrade and a new power supply. Let me know if you'd like guidance on any of these components! 
It looks like you're asking for clarification on why you need extra RAM. You mentioned considering a 64 GB upgrade and wondering if using 2x32 or 4x16 might work better for running XMP properly. You also want to explain your plans so the upgrade makes sense.
For the cooler I’d choose the FC140: https://www.amazon.com/Thermalright-TL-D...B09JZ7B32Q For the CPU, opt for the 5800x3D: https://www.amazon.com/AMD-5800X3D-16-Th...B09VCJ2SHD Remember, stick to a budget and test if you can upgrade to AM5 with your 3070. A newer PSU would also be wise soon.
The purpose is determined by your needs. For casual gaming, the 5900X may not significantly impact performance unless you're pushing hardware limits. Upgrading to it with more memory can offer better stability and smoother gameplay, but the gains might be modest. If you rely on productivity or content creation, the improvement could be more substantial as it reduces strain on your CPU and RAM usage.
It's common to use the PC mainly for gaming, but you're looking for a more versatile setup since you also enjoy 3D rendering and modeling. With your current 16GB RAM, performance starts to drop when running games with many mods or extra content. A upgrade to around 36GB would likely provide a smoother experience.
Add another 2x8 kit and it looks like a waste unless you can find something around $200 used.
The top CPU boost for gaming comes from the Ryzen 7 5800X3D or later models like the 5700X3D when the cost gap exceeds $25. These processors match the performance of Intel i7 12700K and AMD Ryzen 7600 series in most titles. They outperform any other AM4 chip in gaming scenarios. A 5900X delivers similar power by merging two 5600X units, offering near identical results in most games. For CPU tasks that demand many threads, like rendering, speed can nearly double. The 5900XT combines 16 cores (two 8-core units) at lower speeds compared to the 5950X but matches its price. A standard 5700X or 5800X provides two extra cores in the same core group as the 5600 series. Games requiring six cores or fewer see no significant gain over the 5600. For streaming and gaming, simply add two more identical RAM sticks—32GB should suffice. Dual-channel with dual memory will give a slight performance edge. A better cooling solution is required, but a PSU upgrade isn’t necessary. The assassin 120 remains the top choice.
Thanks a lot for your kind words! The 5800X3D sounds like a solid choice. With your RAM at 3200MHz, upgrading to a full 3600MHz could make a big difference. Let me know if you'd like more details!