Does graphic card existence impact unity workflow?

Unity Engine
1

  1. So when work at desktop, desktop graphic card’s existence impact on unity editor’s work performance?
    Currently I am using intel HD4600 (internal graphic).

  2. If graphic card needed, how strong it should be?
    Radeon R7 260, Geforce 750 grade?
    or more strong?

2

I am using an HD4600, and I have no issues with performance.

It will really depend on what kind of games you are going to be making. If the game isn’t graphics intensive then you don’t need a high end card to make it. Best is to try it out and if you find performance not to your liking then an upgrade to video card may help. CPU/RAM also plays a roll. Development usually requires more power to develop then the final product will need to run at full. The game running and the editor running monitoring the game, will eat up a lot of CPU and memory.