Is it okay to run two different graphics card on the same pc?

Solution 1:

Graphics memory and performance doesn't sum up.

Some GPUs can run in tandem if you have two identical cards (SLI/CrossFire), but even then it doesn't just give you 2x performance, many games can't utilize dual GPUs.

With 1050 Ti + 1650 you'll have to use one or the other, not both. Keeping both in a PC would only make sense if you'd want to connect more monitors and hit one card's limit.