What does the rx/0 algorithm mean in XMRig?

rx/0 is XMRig’s name for the original RandomX mining algorithm—the version Monero uses. If you see rx/0 beside a Monero mining job in XMRig, that is normal: it tells you which calculation method your miner is running, not an error or a speed setting.

What the label means

XMRig is mining software that runs directly on your computer. An algorithm is the set of calculation rules it follows when trying to earn mining rewards.

In XMRig’s naming system:

• rx identifies the RandomX family of algorithms.
• /0 identifies the original RandomX variant used by Monero.

The zero does not mean you are using zero processor cores, earning nothing, or running an outdated Monero algorithm. It is simply part of the algorithm’s name.

XMRig supports other RandomX variants for other coins. Those can have different labels and rules, so “RandomX” alone is not always specific enough when you are choosing an algorithm.

Why Monero jobs show rx/0

Monero switched to RandomX on November 30, 2019, replacing its earlier CryptoNight-based algorithms. As of 2026, rx/0 remains the correct XMRig algorithm identifier for Monero.

RandomX favors your CPU, the main processor in your computer. It uses a changing mix of calculations and memory access to make ordinary processors competitive with specialized mining hardware.

When XMRig receives work from a mining pool—a service where miners combine their work—it may show algo rx/0 in the job message. That means the job uses the expected algorithm.

However, the label alone does not prove that you are connected to a trustworthy pool or that your rewards will arrive. You still need the correct pool address, wallet settings, and payout terms.

What it means for your settings

If you are configuring XMRig manually, you may encounter these pool configuration entries:

• "algo": "rx/0" explicitly selects the original RandomX algorithm.
• "coin": "monero" tells XMRig which coin you intend to mine.

You do not necessarily need to set both. Depending on your configuration and pool connection, XMRig can select the appropriate algorithm automatically. Use a current XMRig release and follow your chosen Monero pool’s setup instructions rather than copying an old CryptoNight configuration.

Changing rx/0 to another algorithm name will not make Monero mining faster. It can instead make your miner perform calculations that the pool cannot accept.

What the label does not tell you

rx/0 identifies the algorithm, not how well your computer runs it.

RandomX’s fast mode uses a 2,080 MB dataset, a large working collection of data in memory. Its light mode uses a 256 MB cache, a smaller working store, but runs much more slowly. The /0 does not select either memory mode.

For efficient CPU mining, allow about 2 MB of L3 cache per mining thread. L3 cache is fast memory inside your processor; a thread is one stream of work. Using every available thread is therefore not always fastest.

To judge performance, look at your reported hashrate, meaning calculation attempts per second, and accepted shares—the work your pool accepts—not just the algorithm label.

The bottom line

Seeing rx/0 in XMRig is expected when you mine Monero. It means “original RandomX,” and it is an algorithm identifier—not a warning, performance rating, or earnings estimate.