Why does XMRig say "cpu disabled" or "no active backends"?
XMRig usually says “cpu disabled” when CPU mining is switched off in its settings or unavailable in the version you are running. “No active backends” means it has no working mining engine to use—for example, CPU mining is disabled and neither graphics-card engine is active.
What these messages mean
A backend is the part of XMRig that sends mining work to a piece of hardware. XMRig supports a CPU backend for your computer’s processor, plus optional backends for graphics cards.
Monero uses RandomX, its mining algorithm—the rules your computer follows to do mining work. RandomX favors CPUs, so the CPU backend is normally the one you want.
These messages do not, by themselves, mean your wallet address is wrong or your mining pool is offline. A mining pool combines work from many miners. Pool connection problems generally produce separate messages about connections, logins, or rejected work.
First, check the configuration XMRig actually uses
Open the configuration file loaded by your running copy of XMRig. It is usually named config.json, but a launcher or startup script may select a different file.
Find the "cpu" section. CPU mining should be enabled there:
"cpu": {
"enabled": true
}
This is only a configuration fragment, not a complete file. Change the existing setting rather than replacing your whole configuration or adding a second "cpu" section.
Then:
- Save the file and restart XMRig.
- Read the startup output again.
- Check whether your shortcut, script, or launcher selects another configuration.
- If you use a management tool, check whether it rewrites your settings when XMRig starts.
If XMRig still reports CPU mining as disabled, your edit may not be reaching the running program. Also check the launch options for settings that override your file.
If CPU mining is enabled but still will not start
Look at the messages immediately before the failure. They often identify the actual cause.
Possible causes include:
- A build without CPU support. A build is a particular compiled version of the program. An unofficial or specially compiled copy may lack the backend you need.
- An unsuitable thread configuration. A thread is one stream of work on your processor. A manually edited RandomX profile may leave no usable mining threads.
- Memory allocation failure. RandomX fast mode uses a dataset of about 2,080 MB, plus additional memory. A low-memory device or a restricted container may fail to provide enough.
- A hardware or operating-system mismatch. You need an XMRig release suitable for your processor and operating system.
If you have heavily customized the settings, test a fresh configuration with automatic CPU setup. Keep a backup of your old file.
Avoid fixes that target the wrong problem
Missing huge pages, a memory feature that can improve mining speed, usually reduces performance rather than disabling CPU mining. Likewise, an MSR warning concerns processor tuning; it normally does not mean the CPU backend is unavailable.
Do not immediately disable security software or run everything as administrator. Get XMRig from its official project source, verify the download, and only mine on devices you own or have permission to use.
The bottom line
Check "cpu": {"enabled": true} in the configuration XMRig actually loads. If that is already correct, use the earlier startup messages to distinguish a missing backend from a thread, memory, or compatibility problem.
