There renderers that use the CPU - CPU renderers, there are used video processor - GPU renderers. Hybrids, which would use both, that is, for example, CPU renderer, used to accelerate more and GPU - yet.
In other words, the card is that it can not be used as an additional accelerator, it can act as a separate module rendering and you have to choose, either to render only the processor or graphics card to render only.
At this point, the functional for the CPU renderererov a significant advantage over those that just-rendered graphics forces.
The card is necessary for a good performance in-viewport, that is, to "quickly spun" ranges when working with a stage, for example, when modeling or "seating" hundreds of trees to render the exterior. Moreover, there is a ceiling capacity of the viewport-engine and after a certain level of performance, the benefits of "super-duper" cool graphics in 3ds Max simply will not. In an article about choosing a video card it only on the viewport-performance, not talking about GPU redneringe speech.
If we talk specifically about your case, my personal opinion, if you're not going to play it in the game, then rent it and take something twice as modest. Or rather Look at the recommendations in the above article. As a result, less buzz, warm and guzzle electricity will be, and the release of the money still buy the RAM, or capacious SSD drive 😉