AMD Ryzen 9 3900X CPU Review New BIOS Performance Tested

The Subject of Excessive Voltages

Many people seem to be under the impression that AMD’s Ryzen 3000 series boost clock issues may be related to its high voltages. Its true that many utilities such as Ryzen Master do indeed report extremely high voltages when the system is set to use Precision Boost 2 or Precision Boost Overdrive. These are both automatic overclocking features of these CPU’s and as a result, voltages are largely controlled by AGESA code and the motherboards themselves. AMD has actually posted about this on Reddit and you can see that for yourself here. We won’t regurgitate all that’s said there but rather, we will summarize what was said.

Essentially, you can get false positives running multiple monitoring programs and even seemingly unrelated software packages can create a “race condition” as they call it and trigger these seemingly excessive readings. AMD recommended CPU-Z for monitoring these voltages and using it alone at the time to watch clocks and voltages.

We have actually done this and CPU-Z can still report voltages in the 1.4-1.5v range. According to AMD, its not uncommon or unhealthy for your CPU to periodically use higher voltages to achieve the desired boost clocks. These CPU’s can briefly idle some CPU cores and you can even see voltages under 1.0v at times. AMD recommends setting your motherboard to automatic or “normal” for voltage in the BIOS when using PB2 or PBO.

Our take on this is that CPU-Z has sometimes shown erroneous readings for CPU voltages in the past. We’ve set many systems to manual voltage only for it to read way above or well below what I’ve set. Modern CPU’s, even with manual voltage control do not always use the full amount of voltage specified so this is normal. Essentially, we wouldn’t worry about what your voltages say so long as your thermals are in a good range and that you are seeing boost clocks that make sense for your thermal solution.

During our initial review, we saw temps that never exceeded 78c with all cores manually overclocked to 4.3GHz. Under PB2 we rarely saw temperatures above 65c. Most often, it stayed around 58c-62c according to Ryzen Master. Seeing the voltage going all over the place doesn’t generally concern us given the temperatures we saw. Our VRM’s also stayed relatively cool and as a result, we didn’t see any reason to freak out over the voltages.

Voltage behavior may change as new AGESA code is released and the platform matures, but even if it remains as it is, we wouldn’t generally worry about it. Our recommendation is to use automatic values for PB2 or PBO and use manual control for all core overclocking if that’s what you want to do. It won’t pull that much voltage all the time and you can set limits your comfortable with.
We ran at 1.35v with all the cores overclocked and again, it never broke 78c. That’s not cool, but by no means is that throttling or panic territory. It’s a 12c/24t CPU, so when you push it the thing is going to get hot and suck up some power.

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