CPU Mining in 2026: Is It Worth It, and Which Coins?

An idle desktop can turn spare CPU cycles into a little Monero. Little is the operative word.

The decision rests on four measurements: hashrate, XMR earned per day, electricity price, and power at the outlet. Buying a computer for this usually fails the test.

The bottom line, up front

• Start with Monero (XMR). Its RandomX proof of work is designed to run efficiently on general-purpose CPUs.
• Expect small money. Even a fast desktop CPU produces a fraction of one XMR per day.
• Measure electricity at the wall. A CPU package-power reading omits the rest of the computer and power-supply losses.
• Never buy hardware to do this. Use the formula below on a computer you already own before installing anything.
• Treat the download as the main safety decision. Get XMRig from its official release channel and verify its checksum.

That is enough to make the call. The rest of this guide shows where each input comes from and how to replace it with your own.

What CPU mining is and why it still exists

Most proof-of-work networks stopped rewarding ordinary desktop CPUs years ago. Bitcoin mining runs on specialized ASIC hardware (the Bitcoin wiki’s mining hardware comparison tracks ASICs only), while Ethereum switched to proof of stake in September 2022 and is no longer mined. Monero took a different route.

RandomX’s reference documentation describes random code execution and memory-hard techniques. That favors CPUs over GPUs. The same documentation says efficient mining needs 2 MiB of L3 cache per thread and large-page support, along with at least 2.5 GiB of free RAM per NUMA node, and that multiple memory channels may be required.

That design keeps CPU mining viable. It does not guarantee that a specific CPU, tune, or electricity rate makes money.

Is CPU mining profitable? The actual math

Here is the whole calculation:

Daily profit = (your XMR per day × XMR price) − (watts ÷ 1000 × 24 × your $/kWh)

This worked example is hypothetical. I did not test it. It starts with XMRig’s validated Ryzen 9 7950X benchmark row, which recorded 26,959.77 H/s on one Linux system with 32 threads and DDR5-6600 memory; on September 5, 2026, the live CoinWarz Monero calculator showed an XMR price of $540.84, an estimated network hashrate of 6.41 GH/s, a 0.6 XMR block reward, and 720 blocks per day. Applying those network inputs to the benchmark hashrate gives about 0.00182 XMR/day, or $0.98/day gross before pool fees.

For power, the example assumes 170W whole-system wall power and 24-hour operation. The XMRig row reports hashrate only, not watts; 170W is an assumption to replace with your own meter reading. CPU package power is incomplete. Wall power includes the motherboard and memory, plus fans, storage, graphics hardware, and PSU conversion loss; the outlet reading is the number that belongs on an electricity bill.

The table excludes pool fees, downtime, hardware wear, and taxes. It also freezes price and difficulty at one moment. For comparison, the most recent EIA monthly table when this page was checked (September 5, 2026) gives a U.S. residential average of 18.34 cents/kWh for June 2026, in EIA Electric Power Monthly Table 5.6.A.

If the machine would otherwise be off, use its full mining draw at the wall. If it already runs 24/7, measure both idle and mining draw with the same wall meter; the incremental difference is the added mining load. Do not substitute the CPU’s software-reported package power for either measurement.

Buying hardware remains a poor bet. At the example’s $0.57/day net at $0.10/kWh, recovering $600 takes roughly 1,044 days. At the EIA national-average rate it takes about 2,560 days, or seven years. Both figures freeze today’s favorable price and difficulty in place for years, which reality will not do. Mining spare cycles on a homelab computer you already keep running is the narrower case worth calculating.

Which CPUs mine well

RandomX results depend on more than the model name. Cache per thread, memory channels and timings, huge-page support, operating system, firmware, thermal headroom, and power limits all move the result. A leaderboard entry reports one configuration. It cannot promise the same speed from every chip with that label.

• High-end desktop: the sourced 7950X run above reached 26.96 KH/s. Use it as a configuration example.
• Mainstream desktop: search your exact processor and compare several submissions rather than borrowing a broad six-core or eight-core range.
• Old or low-power hardware: hashrate alone is not enough. Measure hashes per watt for the complete machine, because platform overhead can dominate.

Use the XMRig RandomX benchmark index for validated submissions. Before comparing rows, check the CPU and thread count, then inspect memory, miner version, and sample duration. XMRig’s RandomX optimization guide explains how cache and memory channels interact with huge pages and NUMA settings.

Fast dual-channel memory can help when bandwidth limits the miner, but do not buy a DDR5 kit on that sentence alone. Benchmark your present configuration first. The same caution applies to a Ryzen 7 7800X3D: extra cache is useful only when the complete tune and power result support the purchase.

How to mine Monero safely

1. Create a Monero wallet. Record the receiving address before configuring a miner. The official GUI and CLI wallets from getmonero.org are the reference options; download nothing from a search-ad or forum link.
2. Choose pooled or decentralized mining. A single desktop is unlikely to find blocks at a useful cadence by itself. A conventional pool smooths payouts; P2Pool avoids a central pool operator.
3. Get XMRig from the source. Use the official XMRig releases page, then compare the downloaded file with the checksum published for that release.
4. Tune one change at a time. Follow the official optimization guide for huge pages and cache behavior, then set the thread count deliberately. Watch accepted shares and temperatures under sustained load.
5. Measure the outlet. Record idle and mining watts with a wall meter, then replace 170W in the formula. A PSU wattage estimate is useful for capacity planning, but it is not a utility-bill measurement.

The part that matters most: do not get owned

XMRig is open-source software with legitimate uses. It is also deployed without consent: Microsoft documented XMRig as the usual miner implant in LemonDuck attacks in July 2021; the tactic is old and still current. A security alert identifies mining behavior; it does not prove who installed the file or whether that copy is safe.

• Download from XMRig’s site or its linked GitHub repository. Verify the checksum before any antivirus exception.
• Never trust a forum attachment, video-description link, or build promising double hashrate, an AV bypass, or an unlocked fee.
• Do not disable system-wide protection to make a miner run. If the file source or hash does not match, delete that file.
• Watch temperatures, stability, accepted shares, and outlet watts. A sustained all-core load deserves the same caution as any long stress test.

Where these numbers come from

This guide is desk research. I did not run XMRig, benchmark a Ryzen 9 7950X, measure a computer with a wall meter, or operate a Monero miner firsthand. The hashrate comes from one validated third-party XMRig submission. The earnings figure is a September 5 calculator model, and 170W is a clearly marked hypothetical whole-system assumption.

The arithmetic is reproducible: substitute your measured hashrate and wall power, then read the current XMR price and network inputs from a live calculator. Results can change between visits. The benchmark establishes hashrate for its submitted configuration only; it does not establish power draw, your system’s speed, or future income.

The honest verdict: who should, and who should not

Try it if: you already own the CPU, can verify the miner, will measure wall power, and are comfortable earning a small and volatile amount. An always-on homelab can have a lower incremental power cost than a desktop switched on solely to mine.

Skip it if: you need to buy hardware, cannot verify the download, pay more than your calculated break-even rate, or expect dependable income. The payback and cents-per-day margin are conditional on your own hashrate, wall draw, electricity price, fees, XMR price, and network difficulty. Change any one of them and the verdict can flip.

Mine the math first. If your measured inputs do not clear the cost with room for volatility, stop there.

Sources

• EIA Electric Power Monthly, Table 5.6.A: residential electricity prices by state
• RandomX reference implementation and design notes
• XMRig RandomX optimization guide
• Validated XMRig Ryzen 9 7950X benchmark result
• XMRig RandomX benchmark index
• CoinWarz live Monero mining calculator
• Official XMRig GitHub releases
• Microsoft Security: XMRig deployment in LemonDuck attacks