Nvidia limits their consumer GPU cards to two simultaneous decodes. This can be bypassed with hacked drivers. See elpamsoft page for details.
Ryzens generally provide a much better “bang for the buck” than Intel. However, if you need hardware accelerated transcoding, the lack of integrated graphics may change the value proposition, since you have to figure in the cost of the GPU card.
If you do not need a discrete GPU for gaming, etc, Intel CPUs with UHD graphics are very capable when it comes to transcoding video.
So it depends what you are after. Most up to date CPU’s can handle some decent 1080p transcoding on a bunch of simultaneous streams. If you have plex pass and can do hardware acceleration, a GPU is extremely useful especially for future-proofing.
NVIDIA limits their consumer GPU’s to 2 transcodes but there are easy ways to get around it. A 1660Ti (which is a good budget GPU) can handle 5-6 transcodes no problem. It takes a lot of weight off of the CPU.
I have about 20 friends where we using my plex server and the 1660TI (with the unlock), a 6-core Intel CPU (8-series), 16gb of ram does the job, and can probably be pushed further.
One thing to caution you is the 1650 and 1660 are two different chipsets. Do not go for 1650 its actually a different chipset GPU chip TU116 vs TU117
Do yourself the favor and spend the extra $50 to go for the better better GPU. Unlock it and you will get tons of future proof and performance .
My goal was making the cpu do all the transcoding and the gpu to use with with the monitor to i can use the server for adding subtitles for the movies and other small thing