LLR and Genefer are torture tests for CPUs. They consume a lot of power, and run very hot. This is doubly true with the newer AVX CPUs.
I'd suggest running either PPS Sieve or TRP sieve on your laptop, and staying away from LLR. The sieves run a lot cooler. You might even be able to run those 100% of the time, on all cores, without having heating problems. (And if you do have problems running the sieves, definitely stay away from LLR and Genefer.)
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