You'll have to test that for yourself. I remember running it on my Turing GPU before Broadcast was a thing, and I saw frame rate dips while using the program simultaneously. And that's not happening with RTX Broadcast.
While using RTX Voice in Teams, I notice about 6% GPU utilization on my 1650 ti mobile, which isn't a powerful GPU. About 800Mb of VRAM used by it. Co-workers agree that it sounds great and removed the road noise around my house very well. No performance loss noticed as Teams uses my iGPU for drawing frames.