Mining profitability February 2023 (how is the KA3 doing? GPUs on the rise, what about the RTX 4000?)

Every month, we review mining profitability. In this end-of-February 2023 edition (in French), we look at why graphics cards are back in the black, what the new RTX 4000 cards are worth, how the Antminer KA3 coped with the flood of machines joining the Kadena network, and what the main ASICs were earning depending on the price of electricity.

Video from late February 2023: the figures below date from that time. See "What about today?" at the end of the article.

Update: Kadena is dead. The organisation behind Kadena ceased operations in October 2025 and KDA lost more than 60% of its value within hours. The Kadena earnings and Kadena miners (Antminer KA3 and others) covered in this article are no longer relevant.

Graphics cards back in the black

With electricity at €0.10 per kWh, GPU mining was still broadly negative not long before. By the end of February, results were turning positive again, including on older-generation cards:

• Conflux (CFX): one of the only cryptocurrencies recognised and authorised in China, where it is widely used. After a big pump, many miners switched to it and its profitability went back to normal levels: you had to mine it earlier.
• Nexa: the most profitable coin at the time. Its algorithm relies mainly on memory, which gives a second life to older cards with plenty of memory, such as a 12 GB RTX 3060.
• Kaspa and Ergo: you can mine them separately or together through dual mining, a really interesting option that we detailed in our video on Ergo + Kaspa dual mining.
• lolMiner had just released a new version announcing 25% more performance on RTX cards, which we had not yet had time to test.

RTX 4000: the 4070 Ti is the most interesting

For NVIDIA's new generation, we compare the RTX 4070 Ti and the RTX 4080 on a few coins:

• Nexa: 145 MH/s for the 4070 Ti versus 185 MH/s for the 4080, but the 4080 draws 300 W versus 210 W, so the 4070 Ti is more efficient;
• Kaspa: 1,150 MH/s for 130 W on the 4070 Ti, versus just over 1,270 MH/s for 150 W on the 4080. Same story on Radiant;
• Ergo: 133 MH/s for the 4070 Ti, 170 MH/s for the 4080.

The RTX 4090 reaches about 300 MH/s on Nexa, almost double a 4070 Ti. But in our view, if you are looking for a new-generation card, the most interesting one is still the RTX 4070 Ti: very good efficiency, for a price of around €900. The 4080 is much more expensive and less efficient.

The KA3 takes the difficulty hit

Two weeks earlier, the Antminer KA3 was earning €1,200 per month with electricity at €0.10, as we showed in our review of the KA3 and K7. Now that the machine is widely available, it has dropped to €750 per month. The reason: the Kadena network hashrate went from about 300 PH/s at the end of January to 500–530 PH/s.

The KA3 nonetheless remained one of the most profitable miners at the time, in the middle of a bear market. Depending on the price used, closer to €10,000 excluding VAT, our calculator showed a return on investment of 13 to 16 months at the prices of the day, and about 3 months if KDA climbed back to 50% of its all-time high (ATH).

K7, D9, HS3: the other ASICs at the top of the table

• Antminer K7 (CKB): available only recently, it was still earning about €600 per month thanks to the rise in the CKB price. Return on investment of 10 months, and 2 months at 50% of the ATH. Its price remained fairly stable.
• Antminer D9: it mines the X11 algorithm, mainly Dash.
• HS3: it mines Handshake (HNS).

Bitcoin and ETC: longer payback times

• Antminer S19: one of the cheapest machines for mining Bitcoin, at around €2,000 to €2,100 excluding VAT, i.e. close to €2,500 including VAT. The return on investment at the prices of the day was not spectacular: 30 months at 50% of Bitcoin's ATH, 6 months at the ATH.
• Antminer S19 XP (141 TH/s): a price that was still quite high, for a return on investment of 49 months at the prices of the day and 10 months at Bitcoin's ATH, set at €56,000 in our calculator.
• GT Miner: for ETC and the other coins of the Ethash family (ETHW, ZIL…), it is one of the most interesting miners in our view, with 600 MH/s for 400 W and a fairly stable price. Return on investment of 47 months at the prices of the day, 14 months at 50% of the ATH and 7 months at ETC's ATH.

Prices are shown excluding VAT, to give a trend.

The price of electricity changes everything

With electricity at €0.05, which does exist, payback times become very attractive: 16 months for an S19 bought cheaply (4 months at Bitcoin's ATH), 12 months for the KA3, 8 months for the K7, and 20 months for the Antminer L7, i.e. under two years (between 3 and 5 months if its price moved back towards its ATH).

Conversely, with electricity at €0.17, the residential rate in France, it is very difficult: Bitcoin mining is loss-making. Our advice: aim for €0.12 at most, for example with EDF's Tempo plan (around €0.12 to €0.13) or solar panels.

What about today?

These figures are no longer relevant. The Kaspa ASICs that arrived in 2023 (IceRiver, then Bitmain's KS series) made Kaspa GPU mining marginal, and the April 2024 halving cut the Bitcoin block reward from 6.25 to 3.125 BTC. As for Kadena, the company announced in October 2025 that it was ceasing operations; the blockchain keeps running thanks to its miners, but the KDA price fell sharply.

For an up-to-date estimate, use our Bitcoin mining profitability calculator and browse our ASIC miners. Electricity too expensive at home? Have a look at our miner hosting, or contact us for advice before you buy.