Comparison of PWM Fan and DC Fan Operation
Comparison of PWM Fan and DC Fan Operation
This PC uses a micro ATX design with only one Fan Hub on the motherboard, specifically for CHA fans. It can switch between DC and PWM control via the Asus Bios in Q Fan control. I have a cable connecting the CHA fan header to a 5 Way Splitter. When operating in DC mode, the system experiences rapid speed changes—rising to full power and then fluctuating between slow and fast over roughly 20 seconds. This behavior is unsettling. I’m wondering if this instability might have contributed to the failure of my previous power supply, which died after just two months. Recently I installed a new PSU, but it’s performing poorly. Observing how DC versus PWM settings affect performance has become increasingly important, as the rig tends to slow down significantly and then accelerate again. Eventually, it would crash completely, displaying a black screen before restarting and returning to normal until it eventually fails again.
5 fans on a single header? Are they all the same? These headers are rated for 1A, which means you might not have enough power when they run at high speeds. Check the power of each fan and add them together. If any exceed 1A, you'll need a powered hub. It's not advisable to have different fans on one header since they can send conflicting speed signals to the controller.