strong cpu no gpu

Moved to the hardware forum.

It depends on the CPU platform. A higher-end platform requires a GPU just for the system to even work at all. In that particular case, then make sure that the GPU's memory throughput is higher than the throughput of that system's main RAM. (After all, it makes no sense whatsoever to buy an i7-7820X based system and then equip it with only a GeForce GT 1030 GPU, which may result in the entire system perform significantly slower than it should even if the GPU isn't utilized at all.)

On the other hand, the current Coffee Lake i7 CPUs have integrated Intel UHD Graphics, with outputs on the motherboard that are associated with that IGP. Without an IGP, a GPU would still be required to even work at all. However, the IGP is weaker than even a decent inexpensive GPU (as I discovered in my own personal testing).