How important is graphics card in Premiere and AE?

That GPU is pretty much a waste of a slot in the computer. Move up to a 1070 or better, you'll find that for the things that Premiere uses the GPU for, it will work much better.

For use of the GPU, look over the GPU Accelerated Effects List ... it's things like Lumetri/color, Warp stabilizer, and major frame-size resizing. The GPU isn't used for basic playback when there aren't GPU Accel effects involved.

GPU Accelerated Effects: https://helpx.adobe.com/premiere-pro/using/effects.html

Neil

https://blogs.adobe.com/creativecloud/cuda-mercury-playback-engine-and-adobe-premiere-pro/ may help

The answer to that is largely the mismatch in memory throughput between the system RAM and the GPU's discrete RAM. If that GT 710 uses only DDR3 memory, its memory throughput is only 14 GB/s while the throughput of your system's main RAM (assuming that you're using DDR4-2666 RAM) is 43 GB/s. That mismatch will prevent the CPU from coming anywhere close to its maximum utilization even if the program demands it, causing even everyday apps to lag. In other words, your CPU is being choked out by the lousy GPU card. When looking for a discrete GPU, look for one with a memory throughput that's equal to or greater than the throughput of your system's main RAM for best everyday performance.

And you will not attain much if any GPU acceleration with that GT 710 because it has only 192 CUDA cores, whereas most of the GPUs that we recommend happen to have more than 1,000 CUDA cores.