For Pr & Ae, GPU only kicks in during timeline scrubbing (render & playback) or during GPU accelerated effects. You don't need lots of GPU power if you don't use a lot of GPU accelerated effects, but you will NEED more cores at higher clock speed for encoding, which is the most time consuming act. I have a 1070 coz I don't use tons of GPU effects, but I do have to encode often and the 3900X saves a ton of time during encodes, believe me it was not a good feeling when encode used to take 4 hours on 6900K and the output file had a minor issue that needed to be fixed and re-encode for 4 hours. Now, depending on the project, my encodes on a CPU H.264 2160p High 5.2 CBR 100 Mbps takes around 20-30 mins to finish. You can prioritize your hardware accordingly and if short on cash then divert your GPU funds to CPU, get 3900X with a 1660ti, you don't need RTX in Pr&Ae.