4 threads, minimum usage

Question

In cpu mining, when I set my threads to 4, my cpu is being used up to 75%. I want it to be as low as 18%.

I want all my cpu cores to be used, not focus on one, and get up to around 18 to 20 percent. How do I set a usage percentage for each cpu core? I want to make around 15% use of each.

This is the configuration of my cpu miner (XMRIG). I heard it is about cpu-affinity and cpu-priority but I don't know how to use the values.

{
    "algo": "cryptonight",  // cryptonight (default) or cryptonight-lite
    "av": 0,                // algorithm variation, 0 auto select
    "background": false,    // true to run the miner in the background
    "colors": true,         // false to disable colored output    
    "cpu-affinity": null,   // set process affinity to CPU core(s), mask "0x3" for cores 0 and 1
    "cpu-priority": null,   // set process priority (0 idle, 2 normal to 5 highest)
    "donate-level": 5,      // donate level, mininum 1%
    "log-file": null,       // log all output to a file, example: "c:/some/path/xmrig.log"
    "max-cpu-usage": 25,    // maximum CPU usage for automatic mode, usually limiting factor is CPU cache not this option.  
    "print-time": 4,       // print hashrate report every N seconds
    "retries": 5,           // number of times to retry before switch to backup server
    "retry-pause": 5,       // time to pause between retries
    "safe": false,          // true to safe adjust threads and av settings for current CPU
    "threads": 4,        // number of miner threads
    "pools": [
        {
            "url": "pool.com:80",   // URL of mining server
            "user": "#address",                        // username for mining server
            "pass": "x",                       // password for mining server
            "keepalive": true,                 // send keepalived for prevent timeout (need pool support)
            "nicehash": false                  // enable nicehash/xmrig-proxy support
        }
    ],
    "api": {
        "port": 80,                             // port for the miner API https://github.com/xmrig/xmrig/wiki/API
        "access-token": null,                  // access token for API
        "worker-id": null                      // custom worker-id for API
    }
}

Answer 1

XMRig will always use 100% of a core, it is not possible to go lower. max-cpu-usage does not limit usage on a core, but only limits how many of your total cores are used and it is overriden by the threads option.

The best you can do is to set cpu-priority to 0, this means all other processes will be preferred and XMRig will only use unused CPU resources - at least in theory, in practice you might still experience some slowdown.