Should I use hyperthreading when mining with XMRig?

Usually, you should leave hyperthreading enabled, but do not assume XMRig should use every thread your CPU offers. Start with XMRig’s automatic settings, then compare fewer and more mining threads to find what gives you the best speed, power use, and everyday comfort.

What hyperthreading actually adds

Hyperthreading lets one physical CPU core handle two streams of work, called threads. AMD calls its version simultaneous multithreading, or SMT. Your operating system shows these as extra logical processors, but they are not extra physical cores.

For example, a CPU with 8 physical cores might show 16 logical processors. Running 16 mining threads does not mean you will mine twice as fast as with 8. Those threads share parts of the same cores.

Monero uses RandomX, a mining algorithm designed to favor CPUs. Extra threads can help keep a core busy, but they can also compete for resources and make mining less efficient.

Check your cache before adding threads

One important limit is L3 cache, a small, fast pool of memory inside your CPU. RandomX needs about 2 MB of L3 cache per mining thread for good performance.

As a rough starting point:

• A CPU with 16 MB of L3 cache has room for about 8 mining threads.
• A CPU with 32 MB of L3 cache has room for about 16 mining threads.
• That does not guarantee the larger thread count will be faster.

Cache layout matters too. Some CPUs divide their cache between groups of cores, so the total listed on the box does not tell the whole story. Memory speed and other shared resources also affect the result.

RandomX’s fast mode also uses a dataset of about 2,080 MB in system RAM. That is separate from L3 cache and is not another 2 GB required for every mining thread.

Test thread counts instead of guessing

XMRig is mining software you install and run directly on your computer. Its automatic configuration is a useful baseline because it considers your CPU and available cache.

To see whether hyperthreading helps your setup:

1. Run the automatic configuration first. Let the computer warm up and its mining speed settle.
2. Try fewer mining threads. Where practical, test one thread per physical core.
3. Try additional threads. Add them gradually, especially if you have enough cache.
4. Compare equally long runs. Keep other programs, cooling settings, and XMRig options unchanged.

Watch hashrate, the number of mining calculations completed each second. Use an average over several minutes rather than a brief peak.

For a precise one-thread-per-core test, CPU affinity—assigning a mining thread to a particular logical processor—can matter. Simply choosing eight threads does not always guarantee they run on eight separate physical cores.

Keep extra threads only if they help

Higher hashrate is not always the better result. Compare power drawn at the wall, temperatures, fan noise, and how responsive your computer feels.

If extra threads add little speed but noticeably increase power use, fewer threads may be the smarter choice. On a computer you also use for work, leaving some capacity free can make a big difference.

You usually do not need to disable hyperthreading in your computer’s firmware settings. Limit XMRig’s mining threads first; this leaves other software able to use the extra logical processors.

The bottom line

Leave hyperthreading enabled initially, let XMRig choose a baseline, and test thread counts. Keep the extra mining threads only when their measured benefit is worth the power, heat, and reduced responsiveness on your computer.