Fixed-speed fans only know one setting: full RPM, from the second the PC powers on until the moment it shuts down. That single fact is the whole reason the pwm vs fixed speed fan comparison exists, and it is also why the Einarex EX12A ships with a proper 4-pin connector rather than the older 2-wire type.

Quick Answer

The Einarex EX12A costs R249 and uses PWM to let the motherboard vary its speed automatically between idle and its 82.9 CFM maximum. A fixed-speed fan at a similar price would spin at one constant RPM regardless of how hot the system gets, with no automatic adjustment at all.

🎛️ What the PWM wire is actually doing

A PWM fan has four wires instead of three: power, ground, a tachometer signal, and a dedicated speed-control line. That fourth wire lets the motherboard send rapid pulses that tell the fan how fast to spin, adjusting many times a second as CPU or case temperature changes. The EX12A uses this to move between a quiet idle state and its rated 82.9 CFM ceiling without anyone touching a physical switch. A fixed-speed fan skips that control wire entirely, so it has no way to respond to temperature at all beyond running flat out constantly.

Why that matters for noise

Because the EX12A's 40.7 dBA maximum is only reached at full PWM speed, most of the time it can sit well below that figure during normal browsing or light gaming. A fixed-speed equivalent would produce its peak noise level permanently, with no quieter idle state to fall back on.

🔥 How each type handles a heavy load

Under sustained gaming or rendering load, a PWM fan like the EX12A ramps toward its 82.9 CFM ceiling automatically once temperatures climb, then backs off again as the system cools. A fixed-speed fan is already running at that same top output the whole time, so it offers no reserve capacity to react to a spike, and no quiet reward once the load ends. The tradeoff is really about control, not raw top-end performance, since both fan types can reach similar CFM numbers at full speed.

🔌 Compatibility and setup

Most modern motherboards include 4-pin PWM headers as standard, so fitting the EX12A into an existing build usually just means plugging it in and letting the BIOS fan curve handle the rest. PC case fans with PWM support are worth checking for compatible headers before buying if your board is a few years old, though most builds sold in the last decade support the standard without issue.

🧰 Choosing between the two for your build

If your case already has a few 3-pin headers left over and you want simple, predictable cooling, a fixed-speed fan will do the job at a lower cost. If you want temperature-responsive quiet running most of the time with full 82.9 CFM airflow available under load, the Einarex EX12A at R249 is built for exactly that. Anyone assembling a full build around Einarex cases will find the PWM header layout matches this fan without any adapters needed.

Frequently Asked Questions

Can I run a PWM fan on a 3-pin header?

Yes, most motherboards will run it at a fixed voltage instead of true PWM control, though you lose the automatic speed adjustment.

Does PWM control add extra noise of its own?

No, the control signal itself is silent; any noise still comes from the blades and bearing at whatever speed the curve selects.

Is a fixed-speed fan cheaper than a PWM one?

Fixed-speed fans can be slightly cheaper since they use simpler wiring, though the price gap is often small at the budget end of the market.

Will PWM control shorten the fan's lifespan?

No, PWM speed control is a standard feature designed to reduce unnecessary wear by letting the fan spend less time at full RPM.

Ready to upgrade from fixed-speed to proper PWM control? Bring home Evetech's Einarex EX12A case fan (R249) at Evetech, and let fan speed respond automatically to your system temperature.