How to not fry your FPGA Miner

The heat is up and your miner might die a silent death. Don’t waste your money. Don’t burn your miner. Cooling and overheat protection is essential for mining operations. Let’s look into it.

Miners usually get hot while running. Typical operational temperatures are 60–80°C. Therefore a cooling system must be installed. It will maintain the operational temperature range. Fans will accomplish this most of the time. In addition miners should be installed in cool environments. This helps. Of course it’s not always possible. And even the best fan can break. The installation could be faulty, something covers the fan or obstructs the airflow. That’s when overheat protection enters the game.

There are several ways a miner can be permanently damaged due to overheat:

1. The pcb (printed circuit board) can be damaged. The boards expand and contract with temperature changes. Like any other material. A sudden rise in temperature lets the board expand. It may lead to micro-cracks and broken connections on the board. Not good.
2. A rapid temperature increase can damage pcb soldering. At some point components can be damaged or fall off completely. This leads to unexpected behavior or renders the device useless.

Traditional electronic devices monitor temperature. They power off the device if a certain threshold is exceeded. That is a good way to protect your hardware from malfunction or permanent damage. But when it comes to mining, uptime is important. You want to run your miners unattended. As long as possible. You don’t want to look after hardware that was shut down or might be damaged.

Damaged pcb due to overheat

That’s why a sophisticated overheat protection is useful. More than that, its priceless. It may prevent a lot of trouble and expenses. The FPGA Atomminer comes with a 3-stage overheat protection. It goes well beyond a simple protection mechanism. And it automatically tries to restart the miner if it needs to be powered off. Let’s examine all stages.

1. The first stage comes in play when the temperature exceeds 85°C. The Atomminer will begin to skip mining tasks. It reduces its load and therefore its temperature. This is done by the controlling software. An idle miner won’t overheat. A miner that skips shares reduces the workload. Throttling the performance is the first attempt to keep operational temperature in check.
2. The second stage will kick in at 105°C. It’s not done by the software. It is integrated to the onboard controller, the AM-bios. Once it is triggered it will drop all communications with the FPGA. On a physical level.
3. In case stage one and two fail, stage three will be activated. Once 115°C is reached the miner will power down. It will wait until temperature is back below 85°C. It then starts to power up its bios then the FPGA. If temperature readings remain acceptable Atomminer will continue mining.

Most of these processes are located in the hardware. No user interaction needed. The temperature brackets are chosen based on RoHS standard. And internal components temperature recommendations from their manufacturers. The limit for Atomminer is 125°C but everything will be shut off at 115°C. Just to be safe. Here is an example what it could look like in practice. This was an actual test run:

I set up a miner besides the window in summer. No air-conditioning. The sun was heating up the room. The hashrate of the miner dropped to 50% during daytime. At night it was at 70–80%, saving the device from overheat and malfunction.

The overheat protection of AM02 will be more complex then AM01. It monitors all 4 FPGA chips separately. Plus all power supplies. It will provide recommendations and/or warnings regarding operating conditions. It effectively controls each of the FPGA chips independently. All this is to allow a robust mining operation, to keep your miners up and running at all times. Remember it combines with a profit-switching algorithm. This way you will not miss out on potential mining opportunities.

Bottom line: A 3-stage overheat protection outperforms regular overheat protection. It gives extra security for your hardware and extra uptime for mining operations. Your assets are protected under all circumstances. Implementing this kind of precautions I mentioned might save your miner from permanent malfunction. You’re welcome!

Find out more about Atomminer because it takes FPGA mining to the next level.