yttriumDon't bother with NVENC for streaming. In 90% of games (those with movement) it's garbage because of bitrate.
x264 is pretty much it when it comes to streaming. With a desktop i5 I would attempt 720p60 or 1080p30 but wouldn't vary from that, and you might even have trouble with 720p60. You'd need a desktop i7 for rock-solid 720p60 stability. I wouldn't even attempt 1080p60 without an enthusiast 6core+HT i7.
If you're recording locally, NVENC is fine if you turn the bitrate up to around 50mbps.
Have you tried nvenc recently? It's not great but it has improved drastically now since I first tried it about 18 months ago.