Find out the max value for GOMAXPROCS on your machine.

max_parallelism.go

package main

import (
  "fmt"
	"runtime"
)

func MaxParallelism() int {
	maxProcs := runtime.GOMAXPROCS(0)
	numCPU := runtime.NumCPU()
	if maxProcs < numCPU {
		return maxProcs
	}
	return numCPU
}

func main() {
	fmt.Println("MaxParallelism: ", MaxParallelism())
}

The result on my MacBook Air:

$ GOMAXPROCS=10 go run max_parallelism.go
MaxParallelism:  4

On the Raspberry Pi (Cross-compiled using GOARCH=arm GOARM=5 GOOS=linux go build max_parallelism.go)

$ GOMAXPROCS=10 ./max_parallelism
MaxParallelism:  1

Thanks, in MacBook Air M2 this is the result: