Retrofitting the Bitaxe Cooler: Is the Upgrade Kit Really Worth It?

By Dominik Lederer, Founder, Hardware Engineer & Solo-Mining Expert · Published on August 4, 2026 · 7 min read

What happens in the Bitaxe when the chip gets too hot?

The BM1370 sits on a tiny area. At factory settings, it dissipates about 17 watts of waste heat through this area, which is already a decent thermal density. Above about 70 degrees Celsius, the firmware throttles, and above 75 degrees, it shuts down if necessary. A Bitaxe that is in a room with a temperature of 34 degrees in midsummer will lose performance without anything being broken.

It gets more interesting one level higher. DigLucky's manufacturer blog describes the physics behind the BM1370's limits quite unsparingly in its analysis: If the junction temperature rises above 90 degrees, the static leakage current increases exponentially. Higher temperature generates more leakage current, more leakage current generates more power consumption, more power consumption generates higher temperature. A self-feeding spiral.

This is exactly where a cooling upgrade comes into play. It doesn't shift computing power, it shifts temperature. Everything else is a consequence of that.

Does a cooler pay off through additional hashrate?

No. And that's not an opinion, that's a division.

The calculation chain is short. The current network difficulty is 126,231,507,121,868 (mempool.space, August 4, 2026, last adjustment minus 0.7384 percent). The expected time until a block is found is calculated from difficulty multiplied by 2^32 divided by one's own hashrate. At 1.3 TH/s, that's 417,046,303,702 seconds, or 13,224 years. One block yields 3.125 BTC plus transaction fees, which at a rate of 55,434.10 Euros per BTC (Kraken, August 4, 2026, 09:05 UTC, cross-check CoinGecko 55,432 Euros, exchange rate dependent) is around 173,200 Euros. Block value divided by waiting time results in the statistical annual yield.

Configuration	Hashrate	Power	Chance per year	Expected Value	Electricity per year
Factory Setting	1.3 TH/s	approx. 17 W	1 in 13,224	€13.10	€46 to €52
Moderate, 625 MHz at 1,250 mV	1.5 TH/s	approx. 20 W	1 in 11,461	€15.11	€54 to €61
Aggressive, with upgrade cooling only	approx. 1.8 TH/s	34 to 40 W (assumption)	1 in 9,550	€18.14	€93 to €123

Assumptions disclosed: Electricity price 31.1 to 35 cents per kWh. The 1.3 TH/s and 17 watts are the values of our own edition. The 1.5 TH/s at 20 watts come from our own measurement run in July. The power consumption at around 1.8 TH/s is a range and explicitly an assumption: DigLucky states "40W or more" waste heat from a single chip for 1.8 TH/s, community measurements at 900 MHz and 1,250 mV are rather at 34 watts. We have not measured this point ourselves over a full year.

The jump from factory setting to aggressive overclocking thus brings an additional 5.04 Euros in expected value per year and costs 41 to 77 Euros more in electricity. The kit itself costs an additional 69 Euros once. Anyone who buys cooling as a return on investment is making a losing deal and adding to it.

For context: An industrial Antminer with 270 TH/s at 3,500 watts has a 1 in 64 chance per year, but burns 30,660 kWh, i.e., 9,535 to 10,731 Euros in electricity. The Eurojackpot is 1 in 139,838,160 per lottery ticket. We have extensively derived both comparisons in the Expected Value Calculation.

What does the cooling upgrade really buy, then?

Four things, and none of them are in terahash.

First, peace and quiet. A larger heatsink dissipates the same heat at a lower fan speed. The Noctua NF-A6x15 5V PWM in the kit reaches a maximum of 19.8 dB(A) at 3,500 RPM according to the manufacturer's datasheet and runs at 500 RPM with 20 percent PWM signal. With four copper heat pipes under the chip, it simply doesn't need those 3,500 RPM in normal operation. We measured how much difference this makes in the living room in our noise level test.

Second, summer. A device that runs at 55 degrees in winter suddenly hits the throttling limit in August at 34 degrees room temperature. More cooling reserve means: the same clock speed runs through, even during a heatwave. What else helps is in our article on how to keep your Bitaxe stable in midsummer.

Third, lifespan. Electromigration is not a question of if, but of how fast, and it accelerates with temperature and voltage. A chip that continuously operates 20 degrees cooler ages slower. This cannot be expressed in Euros per year, but it is the most honest reason to buy a cooler.

Fourth, leeway. Without cooling reserve, overclocking is not an option, but a gamble with hardware failures. With cooling reserve, it becomes a decision you can make, not one you have to. How to do this technically is described in the overclocking guide.

Cooler, Complete Kit, or Ultimate: What do I need?

Three stages, three very different buyer groups.

The Low Profile Plus Cooler for 29 Euros is the heatsink with four copper heat pipes plus 3D adapter and screws. No fan, no paste. This is the right choice if you already have a usable 60-millimeter fan and a tube of thermal paste in your drawer. Otherwise, you'll buy twice.

The Upgrade Kit Individual for 69 Euros is the full package for one device: heatsink, Noctua fan, Arctic MX-6, cleaning cloth, adapters in ten colors, small parts. For most people, this is the end point. In practice, there is no second purchase after this.

The Upgrade Kit Ultimate for 129 Euros adds two Noctua fans with PWM Y-splitter, plus two full copper heatsinks for the voltage regulators, the Fiat-Breaker-Stand, and a Leicke power supply with 5 volts, 10 amperes, and 50 watts. This combination only makes sense if you actually want to overclock permanently, because from then on, the voltage regulator becomes the bottleneck, and so does the power supply. Which power supply suits which clock speed is explained in our power supply guide.

An honesty at this point, rarely read from a shop: Two of the three stages are oversized for the average buyer. If your Bitaxe is running at 60 degrees in the living room and the fan noise doesn't bother you, then you don't need a kit at all. The most honest reason to buy is a specific problem: too loud, too hot, or the desire to be able to overclock without getting nervous.

How high can a BM1370 actually clock?

Here, a look at physics rather than product promises is worthwhile. DigLucky estimates the factory performance of a BM1370 at 1.0 to 1.2 TH/s at approximately 15 to 18 watts, states 1.5 TH/s as a stably achievable value after chip selection, and sets the absolute physical ceiling of a single chip at 2.0 to 2.2 TH/s. Above that, electromigration begins to break down the chip, and a growing portion of the computing work ends up as a rejected share in nothingness.

Specifically, this means: numbers beyond 2 TH/s for a single Bitaxe Gamma belong in the realm of laboratory cooling, not in the living room. If you see offers online with significantly higher promises for a single-chip miner, you should ask under what conditions this value was measured and how long it lasted. We prefer the opposite approach and state the conservative value.

How do I install the cooler?

The process takes about ten minutes and does not require a soldering station.

1. Disconnect and let cool. Unplug the power supply, wait ten minutes. A chip that was just running at 60 degrees won't forgive hasty fingers.
2. Remove old heatsink and residue. Loosen screws diagonally, carefully twist off the heatsink instead of prying it off. Remove old paste without residue using the enclosed Arctic MX Cleaner, both from the chip and the heatsink base.
3. Apply new paste and mount cooler. Apply a rice-grain sized dot of Arctic MX-6 to the center of the chip, then place the heatsink straight on and screw it down evenly diagonally using the 3D adapters. Do not readjust by twisting, as this will tear the paste film.
4. Connect fan and re-measure. Connect Noctua to the PWM connector, start the device, then observe it under load in the AxeOS dashboard for 20 minutes. If the ASIC temperature drops significantly compared to before and the voltage regulator remains well below its limit, everything is correctly seated. If not: paste too thick, cooler askew, or a screw unevenly tightened.

How does a cooling upgrade compare to other leisure expenses?

	Bitaxe Gamma in the living room	Traditional Lottery	3,500-watt Industrial Antminer
Chances of winning per year	1 in 13,224 for a full block, i.e., 3.125 BTC plus transaction fees. With a cooling upgrade and overclocking to approx. 1.8 TH/s, this improves to 1 in 9,550.	1 in 139,838,160 per lottery ticket for Eurojackpot. The ticket expires after the draw, regardless of how well you cool it.	1 in 64 at 270 TH/s. The best odds of the three, bought with a device that cannot be operated in any home.
Ongoing costs in home office	46 to 52 Euros electricity per year at factory setting, 93 to 123 Euros with aggressive overclocking. The kit is a one-time 69 Euros.	Two lottery tickets per week cost around 200 Euros per year depending on the provider and leave no residual value.	30,660 kWh, i.e., 9,535 to 10,731 Euros per year. Plus noise levels and waste heat that require a separate hall.
Drawer risk (boredom factor)	Low. There is always something to do: adjust clock, monitor temperature, add cooling, update firmware. That's precisely the appeal.	High. Nothing you can influence happens between submission and drawing.	Very high, but for the opposite reason: The device stands still after a few weeks because noise and electricity bill disrupt everyday life.
Learning effect & tangible blockchain fascination	High. Thermal paste, junction temperature, leakage current, difficulty, and expected value become tangible on your own device instead of theoretical.	None. The random number generator remains a black box.	Available, but industrial. You learn to operate infrastructure, not to understand hardware.

A cooler doesn't buy you returns. It buys you peace of mind, reserve capacity, and the freedom to tweak your own device without watching it shut itself down.

Dominik Lederer, Founder Polarblocks

Frequently Asked Questions about Upgrading the Bitaxe Cooler

Does a cooling upgrade provide more hashrate without overclocking?
Only indirectly. At factory settings, a Bitaxe Gamma delivers its 1.3 TH/s even without a better cooler, as long as it doesn't throttle. The benefit lies in summer months and confined enclosures, where throttling would otherwise occur.

What kind of thermal paste should be used on a Bitaxe?
A non-conductive paste in the upper performance segment is perfectly sufficient. Our kit includes Arctic MX-6. Liquid metal should not be used on this board; the risk is disproportionate to the few degrees difference.

Does the cooler fit every Bitaxe?
The adapters in the kit are designed for the Bitaxe Gamma. Older models with a different hole pattern will not fit without modification. When in doubt, ask beforehand rather than sending back later.

How warm can my Bitaxe get permanently?
Between approximately 40 and 65 degrees at the ASIC is normal operation. Above roughly 70 degrees, the firmware throttles, and above 75 degrees, it shuts down. The voltage regulator typically runs 10 to 20 degrees hotter than the chip, and is therefore the value you should monitor first when overclocking.