Bitaxe Hex

A single-chip Bitaxe is a lovely thing, but sooner or later you want more than one ticket in the draw. That’s what the Hex is: six BM1366 chips on one open board, hashing at around 3 TH/s, hunting for a block with roughly three times the odds of a Gamma. It’s still open-source AxeOS, still a hobby miner rather than an income, and it’s still the same lottery. There are just more numbers on the ticket.

The take

I own the single-chip Bitaxes, the Gamma and the Supra, and I’d point most people at those first. The Hex is the one you reach for when a single chip stops feeling like enough, and it makes an honest trade to get you there. Six BM1366 chips do about three times the hashrate of a Gamma and give you about three times the solo odds, but the BM1366 is older silicon than the Gamma’s BM1370, so you pay for those odds in efficiency, in heat, and in a board that’s genuinely harder to tune. Nobody who’s run one calls it plug-and-forget. What you’re buying is more lottery for more faff, which is either exactly what you want or exactly what you don’t.

What the numbers actually mean

3 TH/s sounds like a big jump from a Gamma’s 1.2, and in lottery terms it is: three chips’ worth more chances, near enough, from one box. But look at the efficiency and the older chip shows. The six BM1366s land somewhere in the mid-20s J/TH at stock against the Gamma’s 15, which means the Hex works harder for each terahash it produces. That shows up as power. Where a Gamma sips 18W off a phone charger, the Hex pulls somewhere around 70 to 90W and needs a proper 12V supply to feed it. That is the single most important thing to understand before you buy one: this is not a 5V USB board, and treating it like one is the fast route to unstable hashing.

The store figure you’ll sometimes see, a shade under 20 J/TH, is optimistic. It’s better than the BM1366 chip manages even in Bitmain’s own industrial gear, so take it as a best case and plan around the mid-20s in the real world. None of this is a criticism exactly, it’s just what an older six-chip design costs you. You’re spending efficiency to buy odds, with your eyes open.

The 12V thing, and why it matters

Every single-chip Bitaxe runs on 5V, off a barrel jack or, on the Gamma, USB-C. The Hex does not. It steps up to a 12V input, usually a barrel jack and sometimes a 6-pin PCIe on custom chassis, and it wants a supply that can hold that voltage while six chips pull current together. The community steer is a good-quality 12V unit rated for at least 10 amps, with headroom, and it’s not an upsell. Cheap 12V adapters that sag under load are one of the most common reasons a Hex hashes badly, and the symptom looks like a tuning problem when it’s really a tired plug. As on the rest of the line, the onboard USB-C is for flashing and the serial console only. It cannot power the board, so don’t try.

Overclocking, which is the hard part

On a single-chip board, tuning is a two-box job: pick a frequency, pick a voltage, watch the error rate. The Hex breaks that simplicity because you’re now trying to keep six chips stable at once, and thanks to the silicon lottery no two of them behave the same. Nudge the clock up and one chip will start throwing errors while the others are happy, or the board will spike power in a way a single chip never does. Owners who’ve chased it describe diminishing returns quickly, rising error shares and heat before any clean gain, and most settle for running near stock. If you came from a Gamma expecting to walk the clocks up the same way, this is where the Hex asks more of you. My honest advice, without having lived with one daily, is to treat stock as the setting and any overclock as a careful, per-chip experiment rather than a free hashrate button.

Cooling is part of the same story. One heatsink spans all six chips and a single 80mm fan pulls air across the lot, so there’s real temperature variance from one end of the board to the other. Keep the airflow clear and the room cool, watch the per-chip temperatures in AxeOS rather than a single headline number, and remember that a weak chip in the middle can be cooking while the ends look fine.

Living with one

Firmware is the reason to buy any Bitaxe and it mostly holds up here, AxeOS on an onboard ESP32 serving a web dashboard to any phone on the network, live hashrate and temperatures and your best-ever share. The rough edge on the multi-chip boards is that owners upgrading past the factory firmware to newer mainline AxeOS releases have reported the UI dropping voltage and per-chip temperature readouts while the unit keeps hashing, and at least one documented bug ramps the fan to full when a single sensor misreads and reports a chip at zero degrees. None of that stops it mining, but it’s worth knowing the newest firmware isn’t always the calmest on a six-chip board.

Noise sits between the single-chip boards and a real ASIC. The 80mm fan is a soft hum at idle and climbs to something like a loud laptop when all six chips are pulling in a warm room. It’s quieter than a shrieking commercial miner and louder than a Gamma left at a sane clock, which is about what you’d expect from three times the chips. And as with every Bitaxe, there’s a sacrificial TVS diode across the power input that clamps a surge and blows itself to save the chips, so if a Hex ever comes up dead after a power event, that’s the first thing to check before you write off the silicon.

Who should get one, and who shouldn’t

Get a Hex if you already understand what a single-chip Bitaxe is and you want more solo odds from one unit without stepping up to a full, loud, industrial ASIC. Get one if the tuning challenge of a six-chip board sounds like the fun rather than the chore, and if you’re happy to sort a proper 12V supply and treat the thing as a hobby that costs a bit to run.

Don’t start here. If this is your first miner, a Gamma is cheaper, quieter, more efficient and far simpler to live with, and the Supra is the same story a generation back. Don’t buy a Hex for efficiency or for profit either, because the older chip loses the first and nothing this size wins the second. The Hex earns its place for exactly one reason: more chips, more odds, from one open board you’re willing to fiddle with.