The lower the CPU volts, the better it is.
The lower the CPU volts, the better it is.
I've increased the voltage slightly to maintain stability after overclocking to 4.8 Ghz i5-8600K, Z390-F, 1.25V. Consider keeping it in auto for better performance under load.
It is very difficult to damage a CPU by undervolting, yet it can cause failure or reduce lifespan if you exceed 1.4/1.5 for extended periods (AMD may tolerate slightly higher voltages than Intel, but eventually they fail too).
System stability under heavy use is the main concern. If your PC performs at 95% usage perfectly at around 1.2 volts, but operates at 97% load, it will likely crash.
Increasing the voltage to reach 4.8ghz would probably lead to instability; if the system automatically adjusts to 4.8, there is a chance of success.
If that option is unavailable, proceed cautiously and adjust voltage changes in increments of no more than 0.01 or 0.02 at a time.
At 1.25V with 100% performance, the CPU runs smoothly at 4.79GHz. No changes are necessary unless there are other concerns.
It doesn't matter if you run your PC at full capacity for just a moment or an extended period; it may fail after a short or longer time. That's why pre-built systems undergo stress tests for 24 hours before being shipped.
You have two choices:
- Lower the voltage gradually, such as 0.01 or 0.02, until it crashes immediately after powering on. This indicates you're near the limit. Then increase the voltage until it no longer crashes. This is trial and error.
- Keep the voltage steady or adjust it manually to achieve overclocking. I'm intentionally vague here because you'll need to do some research before proceeding with CPU overclocking.
Something to throw out regarding voltage and whether or not it damages the components or whatever.
The primary cause of damage is excessive current
. Excessive current leads to heat build up. This can exacerbated by a property of semiconductors called
thermal runaway
. Once the part reaches a certain temperature, its resistance decreases, leading to even more current being drawn, which leads to more heat.
Too low of a voltage does not damage the part
. The only issues too low of a voltage causes is instability, which would lead to the system crashing. A system crashing is a
software
problem, the hardware doesn't care.
Too high of a voltage is a problem, but any damage is usually immediate
. This applies to the power delivery or signal inputs. Static discharge events are another story. In any case, when the voltage is too high, it causes insulators to break down and become conductors. In an integrated circuit, this causes shorts, which leads to excess current. Another thing of note is that
the only voltage that's too high is one specified by the manufacturer
.
Most processor companies publish datasheets regarding electrical specifications of their parts. Worryingly, AMD does not provide such a datasheet.
With regards to OP's processor, the i5-8600K, refer to
https://www.mouser.com/datasheet/2/...-f...287458.pdf
, but the short of it is the maximum operating voltage is 1.52V. Therefore, as long as you're not exceeding this,
you're not risking damaging the part
.
Voltage does directly affect heat output
. The formula is P = C * f * V^2, where P is power dissipation (i.e., heat output), C is capacitance (something you can't change), f is the operating frequency, and V is the voltage. Since voltage is squared, it has a higher impact than changing frequency, so obviously lowering voltages can dramatically decrease heat output.
I just wanted to add a brief note, hopefully improving things. Determining the main cause can be tricky; heat is likely the primary factor, though current is a close second. It's important to remember that maintaining cool temperatures significantly reduces the damage from high currents. Some extreme overclockers push very high currents during tests, but they manage to control core temperatures using liquid nitrogen, which keeps them safe. They clearly don’t want their competition’s precious CPU performance.
As you mentioned, both current and voltage contribute to heat generation at a specific frequency. For cooling purposes, voltage is the main adjustable parameter. However, Ryzen processors can run at relatively high voltages—like 1.5V at 5GHz—though only briefly; the boost algorithm quickly restores timing. Under heavy load, when all cores are warm, it constantly adjusts both clocks and voltage to protect them.
The voltage limit is determined by the material properties of the chip. For Ryzen, it must exceed 1.5V during boost phases, as noted by Robert Halleck. He even suggested it could reach up to 1.55V during a cold start. Unfortunately, his insights on Reddit and AMD forums are our only source since those companies don’t share detailed specifications. I doubt he’s exaggerating; he likely has a safety margin in mind.
I recently saw a Buildzoid video demonstrating what happens when an Intel CPU is overvolted. It became very hot, but it only started buzzing above 1.6V. This suggests that even voltages around 1.52V—consistent with the data sheets—likely have sufficient safety margins.