Well, here’s the recommended specs from the UE4 wiki.
- Desktop PC or Mac
- Windows 7 64-bit or Mac OS X 10.9.2 or later
- Quad-core Intel or AMD processor, 2.5 GHz or faster
- NVIDIA GeForce 470 GTX or AMD Radeon 6870 HD series card or better
- 8 GB RAM
This has not been updated for years, for a new desktop computer I’d adjust it to:
- Recent Intel i5/i7 or AMD Ryzen/Threadripper processor
- NVIDIA GeForce 1050ti GTX or Radeon RX 460 or better
- 16 GB RAM
- And a 256GB+ SSD with extra HDD space
Buying previous generation GPU and CPUs don’t often save much money per performance, unless a new product just came out and they are trying to get rid of stock. The amount of vram a GPU has doesn’t tell you much about how it will perform.