Fan
The fan is the only moving part in an ASIC. It is also the first candidate for replacement: the bearing wears out long before the chips get tired.
What to know about ASIC fans
An air-cooled model usually has four of them: two at the front pulling air in, two at the back pushing it out. Size 120 or 140 mm, up to 6000 rpm, which is where the noise comes from. The cable carries four wires: two for power, one for the tachometer, one for speed control.
The firmware watches every one of them. The rpm shows up in the log, and if a fan stops or its tachometer lies, the ASIC drops the frequency or shuts down completely. That is protection: without airflow the board overheats in minutes.
A fan dies gradually. First a hum and vibration at certain speeds, then scatter in the log readings, then it seizes. Dust speeds all of this up: it packs into the bearing and works like an abrasive.
A replacement costs pennies next to any board, but get the original or a proven analog with the same tachometer. Cheap copies spin fine yet report garbage, and the ASIC shuts itself down in the middle of the night.
The short version
| How many | usually 4: two intake, two exhaust |
| Speed | up to 6000 rpm, visible in the log |
| Cable | 4 wires: power, tachometer, control |
| First sign of wear | hum and rpm scatter |
| What not to do | install a copy with a lying tachometer |
How to stretch its life
Keep the air clean: a filter on the intake is cheaper than the bearings of four fans.
Don't push the rpm to maximum without a reason. Eco mode is quieter and gentler on the bearings, because the fans live at medium speed.
Listen. A changed sound is the earliest diagnosis, ahead of any log.
Replace them in pairs, or all at once if the miner is old: the rest are on their way out anyway, and you only open the case once.
Example from a log
An ASIC rebooted overnight, and in the morning the log showed fan speed 0 on the third fan. It still spins by hand, but seizes at working speed. The replacement took twenty minutes including a heatsink cleaning, and it is the cheapest repair there is: any board would have cost tens of times more.
Related terms
Where to go next on the site
Hardware
- ASIC Miner knowledge base
Software
- Software firmware
Questions and answers
Can you run an ASIC without a fan
An air-cooled one, no: the firmware demands rpm readings and shuts the miner down without them. Fans only come off in an immersion tank, and there an emulator fakes the signal.
Why does the ASIC shut down even though the fans spin
Most likely one of them is lying through its tachometer: the rpm in the log jumps around or reads zero. The firmware cares about the signal, not the spinning itself.
Original fan or an analog
Original, or an analog with confirmed tachometer compatibility. Saving money on a copy ends in nighttime reboots that cost more.
How the terms connect
Every link in the chain is clickable. Orange marks where you are now.
Looking for an ASIC miner
The catalog holds 212 models. You can compare them by hashrate and by joules per terahash, then plug your own rate into the calculator and see what stays in your pocket.
Page written and checked by Denys Klimchuk. Updated .