Rysen 5 2400g overclock Problem

[Novajetfire333]

Ok so ive been looking around but i havent seen anything on my problem.
Im a first time system builder and first time overclocker, and im having a very hard time overclocking the vega 11 and getting it stable.
Playing around with the voltages ive managed to get close (Meaning i no longer get video tdr failure or other bsod's) but in gaming i kept having huge frame drop ( From 50-55 down to 10-11 Fps) about 2mins in to my game and it would last for about 10 to 15 seconds go back to normal and about 2 mins later it will do it again and will keep going thru that cycle....
now ive found the problem but im not sure why its happening or how to fix it but... When runnging game in window mode i had ryzen master open i back ground where i could see the yellow cpu speed peak Gage and i noticed that when the fps drop happens the cpu peak speed would drop from 3.9 ghz all the way down to .6 ghz when the cpu package reached 70c and then go back to 3.9 once the temp droped 10c or so (i also confirmed this with hwmonitor.) 
My question is does this seem right? i mean my cpu cooler is rated for 150w tdp im not even hitting half of that.... if any body can help id be really gratefull.
Build....
Asus Prime b540M-A
Ryzen 5 2400G
Be quite pure rock 150 tdp (yes im pretty sure it on right)
Ram Patriot Viper 4 ram 8gb 4x2 3000mz Oc to 3200 stable in dual channel
236 gb western digital sata3 m.2 ssd
thermaltake 500w psu 80+ bronze

Closest stable oc....
cpu clock= left stock
cpu voltage=1.35
Apu gfx clock= 1500mz
Apu gfx voltage= 1.25
Soc voltage=1.175

[bleedblue]

Have you confirmed that this doesn't happen without your overclock?

What are the GPU temps?
Use MSi afterburner's OSD so you can monitor temps and usage in game fullscreen.

[Kenjo]

25 minutes ago, Novajetfire333 said:

Ok so ive been looking around but i havent seen anything on my problem.
Im a first time system builder and first time overclocker, and im having a very hard time overclocking the vega 11 and getting it stable.
Playing around with the voltages ive managed to get close (Meaning i no longer get video tdr failure or other bsod's) but in gaming i kept having huge frame drop ( From 50-55 down to 10-11 Fps) about 2mins in to my game and it would last for about 10 to 15 seconds go back to normal and about 2 mins later it will do it again and will keep going thru that cycle....
now ive found the problem but im not sure why its happening or how to fix it but... When runnging game in window mode i had ryzen master open i back ground where i could see the yellow cpu speed peak Gage and i noticed that when the fps drop happens the cpu peak speed would drop from 3.9 ghz all the way down to .6 ghz when the cpu package reached 70c and then go back to 3.9 once the temp droped 10c or so (i also confirmed this with hwmonitor.) 
My question is does this seem right? i mean my cpu cooler is rated for 150w tdp im not even hitting half of that.... if any body can help id be really gratefull.
Build....
Asus Prime b540M-A
Ryzen 5 2400G
Be quite pure rock 150 tdp (yes im pretty sure it on right)
Ram Patriot Viper 4 ram 8gb 4x2 3000mz Oc to 3200 stable in dual channel
236 gb western digital sata3 m.2 ssd
thermaltake 500w psu 80+ bronze

Closest stable oc....
cpu clock= left stock
cpu voltage=1.35
Apu gfx clock= 1500mz
Apu gfx voltage= 1.25
Soc voltage=1.175

Put your windows energy managing profile to high and stop  windows from shutting down monitor / hdd after 5-45min idle ...