I find it strange your multiplier is 15.5X which means your cpu is running at 1.55ghz. Core voltage is also rather high.
It is not normal for the CPU to down clock to 15.5X, normal XFR is 22.0X. The only time the cpu will down clock is if the multiplier is set to auto, with a manual overclock the cpu will never down clock. Have you by chance been playing around with P-States or perhaps the processor power management in windows power settings? You could also have a cooling issue, what are your temps?
FYI, there is a new cpu-z, you should get it. Version 1.79, here is mine for refference
FYI select the window you want to screen shot then use ALT+PRINTSCRN to capture the window, then paste into paint or something.
Have you found any solution for the problem? I seem to have similar kind of problem. I ran yesterday few benchmarks with my new ryzen 5 1600 and scored only around 480 in cinebench r15. Also 3DMark Fire Strike physics part seemed to be well below expectations. In Fire Strike results was my prozessor "Maximum turbo core clock" exactly in the same region at 1,55 GHz like yours as well.
I didn´t yet have time to run cpu-z but going to try it out asap, as well as check the power management settings in win 10 and try to go through cpu settings in uefi. But if anyone has solution ready, I am more than happy to hear more suggestions since I am with little experience to this.
Basic info of my system, should it be needed:
mobo - msi mortar b350m
cpu - ryzen 5 1600
gpu - msi armor rx580 8gb
ram - g.skill ripjaws V 3200 MHz, 16gb dual kit
ssd - samsung 960 evo 250gb
Yep, looks exactly like mine back then.
I managed to solve it... at least got rid of it. Changed settings few times so that nothing worked anymore, the computer just didn´t muster any signal out of it. After tugging about half my hair out, I found instructions to switch the power off and take the small battery out of motherboard for 15 seconds to even get thing back up and running. Put it back in and started the machine. After that the CPU clock multiplier was normalized and also the performance was there. Now it scores about 1200 cinebench r15. So it seemed that it just needed to get really booted. I´m not aware that I had meddled with the settings other than trying out that msi mobo ready-offered light oc settings but it anyway worked and is worth a try.
Yesterday CPU reduced again to that same 1,55GHz speed. It seemed to happen after updating the uefi/bios. I had turned on that msi gaming turbo feature in bios setup, which then automaticly turned on AMD Coll´n´Quiet feature. First CPU worked fine but after playing GTA V and turning it off, decided the CPU to reduce the speed. I´m sure it was still ok during playing because that has a massive effect to the game. Anyway after that I disabled the game boost and Cool´n´Quiet AND manually set the CPU multiplier to 37 (I think the default is though 32). after the boot everything worked again just fine.