Auto coin switching: when it pays and when it costs you

What a profit switcher does

A profit switcher watches several coins your hardware could mine. It estimates what each would earn right now and moves the rig to whichever looks best. Rental marketplaces do the same for you when you sell hashrate instead of mining with it.

The pitch is simple: always be on the best-paying coin. It is right some of the time and confidently wrong the rest. The comparison it makes is not the comparison that pays you.

It compares estimates, not results

A switcher ranks coins on revenue per unit of hashrate. It works this out from each coin's current difficulty and current price. Both move, and the price moves for reasons unrelated to mining.

So the ranking is a forecast with no error bar. Most of the time, two coins sit within a few percent of each other. Then the ranking is inside the noise.

A switcher acting on it is betting on a coin flip, while paying real costs for every move.

Cost 1: the rig stops while it switches

Switching means restarting the miner. Often the miner must also rebuild a dataset the new algorithm needs before the first share. During that time the rig earns nothing.

Once a day, this is invisible. Every 20 minutes, it is a permanent tax on the whole operation, and it grows with the number of cards.

People discover this cost after a month of switching. Total earnings are lower than before, yet the hashrate charts look fine.

Cost 2: the round you walk out of

This cost surprises people. It depends entirely on how the pool you leave pays. A round is the stretch of work until the pool finds its next block.

• On a scheme that pays per round, your shares are your claim on the block that round finds. If you leave before it does, you took the risk and somebody else takes the reward.
• Some schemes pay on your share of recent history, to discourage exactly this. There, leaving resets your position, and the work you had banked stops counting.
• On a scheme that pays per share, this cost is close to zero. Each share was priced when you submitted it. Leaving costs only the time the switch takes.

So a switcher belongs on pay-per-share, or on a pool you stay with long enough to see rounds through. Switching often across round-based pools keeps funding rounds that pay somebody else.

Cost 3: the dust you leave behind

Every coin you visit leaves a balance somewhere. If it is under that pool's payout threshold when you move on, it stays there.

A switcher that touches 12 coins in a month can leave 12 small amounts stranded across 12 pools. Each one is trivial, but together they are not.

They are often never recovered. Reaching each threshold would mean going back to that coin long enough to earn the rest.

The two settings nobody changes

Almost every switcher offers these two settings. Almost everybody leaves them at the default, and that is where most of the harm comes from.

• The margin. This is how much better the other coin must look before the rig moves. A default near zero switches on noise. Set it wide enough that a move pays for the restart, the abandoned round and the dust it leaves.
• The minimum dwell time. This is how long the rig must stay before it may move again. Without one, two coins trading places produce a rig that spends its day restarting.

When switching is the right answer

• You rent hashrate out rather than mine with it. The buyer carries the coin risk and you are paid for the hashrate. This is the case the whole model was built for.
• The gaps between coins are genuinely large, not a few percent. Now and then one coin moves far enough that the ranking is not a coin flip.
• You mine to sell at once and hold nothing. Then the only thing that matters is revenue this week.

When switching is the wrong answer

• You have one or two cards. The restart cost is the same share of a small rig as a large one. The extra revenue it might capture is small in absolute terms.
• You want to hold a coin you believe in. A switcher optimises this week and sells the rest, the opposite of that position.
• The algorithms involved need a heavy rebuild on every change. The cost per move can exceed anything the ranking difference is worth.
• Your rigs are far from the pools you would switch between. A better coin on a distant server can pay less once stale shares are counted. A stale share is one that arrives too late to count.

What usually works better than switching

Pick a coin for reasons that will still hold next week, and mine it. Let a rig that never stops do the work.

Then review monthly with real numbers, not a live ranking. Compare what your wallet received with what the same hardware would have received elsewhere over the same period.

That comparison is worth making, and worth acting on when the result is clear. It does not need making every 15 minutes. Made that often, it costs more than it finds.