Hey guys my ryzen7 2700x is only on 60-80% load if i try 900p60fps, 8500bitrate,x264 slow preset. but the stream is laging bad and obs has no dropped frames or FPS drops. It is a Dedicated Streaming rig with 16gb ddr4 3200 and an Asus strix gtx1070 connection: cable 200down/50up
That's pretty definitive. Either lower your resolution or drop back to medium -- you're running into encoding limitations. Your CPU may show that it's not running 100%, but that's with skipping frames in order to meet frame timing. You're not able to reach 100% encoding capability based on your current settings.
Set your Power Plan to Ryzen Balanced or High Performance
(There is a difference between the two, they change how XFR and PBO work on Ryzen chips.)
Ryzens have XFR and PBO to overclock the chips over base clock of 3.7GHz. XFR is the equivalent to Intels Turbo boost, PBO is like Nvidias GPU Boost, it overclocks core automatically past the normal XFR clock. PBO is the feature that allows you to reach 4.3GHz on single and low core loads.
There's settings in your BIOS that control how high and how many cores Precision Boost Overdrive will boost, on my ASUS board it's called Performance Enhancer - Levels 1-4.
Level 2 is max AMD limits, 3 and 4 push the settings past the limits, they require watercooling, overclocking tweaks and other fun stuff and may be unstable. Level 2 is generally safe.
Ryzen Balanced lets XFR/PBO do their thing, boost single/multiple cores beyond the normal "turbo levels" based on cooling and other factors. High Performance will all core boost at all times but disables XFR2/PBO for single/low core load overclocking. Your max clock will most likely be 3.9 or 4.0 GHz on all cores.
Encoding is an all core task so High Performance is probably best and you can ignore pretty much everything above, but you should do your research on XFR2/PBO, it is fairly new and information is mixed and they are crucial for getting the most out of your chip.
Hit Windows+i>Goto Gaming
Turn off Game Mode
Turn off Game Bar
Turn off Game Capture/DVR
Set the process priority to High
Set your YUV Color Matrix to 709
This section is so you don't spend cycles re-sampling your audio
Windows Sound Devices/Playback and Recording
Set all of them to 48000 Hz under Properties>Advanced on each device.
You are using the slow preset, are complaining that you have lagged frames, and the log exhibits lost frames due to encoding lag.
The answer is pretty clear: The CPU is overloaded. Use some less cpu-intensive preset, such as medium, fast or faster. There is no perceivable visual difference between slow and fast, anyway.