To clarify, I'm not applying any OC, and running under Windows Balanced. I finally narrowed down the main issue to the voltage being too high by default, oscillating between 1.38 and 1.45v constantly, even on idle. People have suggested that I manually set the voltage, but that means that my processor might not be able too boost to it's maximum state and take advantage of XFR and precision boost.

But I finally found the solution!!

The default, out of the box configuration for the Asrock motherboard is Asrock OC Mode. By changing the default, Asrock OC Mode to AMD CBS mode, at default, and not changing anything else, and booting into Windows, I finally see the processor downvolting on idle, all the way down to .78v. I still get constant random spikes, but what you would expect form bg processes ramping up and down, and idle temperature is acceptable 30-38 degrees on average.

In addition to this terrible default setting, the Asrock bios also has the following 'features':

- Under Asrock OC mode, you can't change DRAM voltage at all. Well, you can change it, but it resets on reboot, so you can't really push dram overclocks at all.

- A second bug is that you can't set DRAM timing to CL15. It's always reset to CL16.

- If you want to OC ram (because of the voltage resetting issue), the only way to do it is to set the timings in the AMD CBS Dram timing settings under AMD CBS OC mode, which is a pain because the values are in hexadecimal. The other option is to set the timings in the Asrock OC mode, hope that you can save and reboot, and then change to AMD CBS OC mode, which gets prepopulated with the correct values converted into hexadecimal (except CL15). Oh, and not forget to set the dram voltage again as it has been reset after a reboot.

- The Fan analyzer tools always detects different speed values for the fan, and come up with stupid curves that lower fan speed as temperature climbs in the second or third state.

- The F-Stream software to Overclock and 'control' fans is useless. Seems to randomly set values for the fans which you can't control.

This is the very first BIOS release for the Asrock x470 itx, and it was released just around 10 days ago (the actual BIOS and the board). I'm hoping that they can quickly improve it, but so far I'm not impressed. I'm actually coming from the Asus x470 itx, which I exchanged after bad costumer support and a faulty m.2 slot. I wasn't impressed with the support or quality control from Asus, but oh boy was the board nice and their software was polished. I'm starting to regret just not exchanging the Asus instead of returning it, although the Asrock on paper had everything I needed too.

I had heard good things about Asrock, but the quality of the software is pretty terrible, and more so after coming from an Asus and even Gigabyte z170 board before. And it isn't even cheap. The only saving grace has been that I'm getting slightly higher Firestrike scores by default with the Asrock than with the Asus.

its an amd issue

it wont allow odd cl numbers unless you turn off geardown mode

I'm also disappointed by quality of bios in my x470 . 

Also have problems with setting my memory to highier speed.

Join  with question what is geardown ? Maybe it will help me too. 

Zen Common Options

page 62/63/64 of the user manual

My X470 Taichi + 2700x has high voltage problem as well. BIOS is all stock setting. The idle voltage can spike up to 1.5V and idle temperature is 40-50. When running prime95 or cinebench, temperature can go up to 80C+ (tdie) and cpu voltage at 1.38 under high load.  CPU boost for all cores is under 3800Mhz. The system is being cooled by a custom water loop, the GPU in the same loop is idle at 32C. Changing to ASRock or AMD CBS mode makes little difference. BIOS version is 1.35A.

If I set the cpu core voltage to a fixed 1.30V, idle temperature will drop down to 30C range. Under stress load, temperature is at the 70C range instead of 80 and voltage drops down to 1.28V. The most important of all is now 2700x will boost all cores up to 4000-4100 range, and single/double thread boost is at 4200-4300.  Cinebench multip-cpu score jumps from 1755 to 1820. So by just choosing just a less voltage value actually makes the system run faster. There should be something very wrong with the default "AUTO" setting.

I've no problem setting up the DRAM voltage. My G.SKILL Ripjaws V 3200 14-14-14-34  (2x16GB) is not stable at default 1.35V. I've to manually set it to 1.38V. I think the board will reset the RAM setting if it detects any problem before POST.

But one thing is for sure the default auto temps is set crazy high and i've yet to undervolt the cpu as i'm still trying to get stable timings above 3200