The specs say this PC supports one M.2 2280 Solid-State Drive (SSD) PCIe 3 x4 NVME, up to 32 Gbps, up to 512 GB. NOTE: Crucial is offering up to 2T SSDs they say are fully compatible with this PC model, and likely other brands offer big SSDs that will also work.  The Service Manual shows how to install an M.2 SSD and you could put Windows and games on the SSD and use the 1T HDD only for storage.  If you have 12 GB of RAM now, that means 1x 8 GB + 1x 4 GB since there are only 2 memory slots on the motherboard. So at least one of those will have to be replaced to get more than 12 GB. This PC accepts a total of 4 GB, 8 GB, 12 GB, 16 GB, 24 GB, and 32 GB combined in the 2 slots.  NOTE: It's always better to install matched RAM modules so memory runs in dual-channel mode, which is faster and more efficient than single-channel mode that mismatched modules run. This PC model has either a 290W or 365W PSU, so that limits your options for video cards, and the GPU will affect game performance...
My son has a 3670 with 12Gb RAM & 1Tb Sata drive.  To boost performance I'm thinking adding a fast M2 PCIe SSD drive & possibly adding more RAM will help with his gaming applications.  Will this PC accept a standard SSD & what & how much RAM would it accept?  Moving his games to the SSD would improve performance noticeably I would assume. Thanks for your thoughts.
Add SSD & Memory to Inspiron 3670?