I got both i7 and i5 versions of these Nuc8 machines and run multiple VMs on each. The i7 can boost all 4 cores to 4.1ghz but gets very noisy (fan noise) very easily when cpu utilization gets above 30% or so. I decided to cap the max turbo frequency at 3.0ghz (via windows power profile registry) to keep the machine running as quiet as possible (just slightly noisier than idle fan noise when I push all 4 cores to 3.0ghz for multiple minutes). The i5 on the other hand runs very quiet even when I push all 4 cores to their max at 3.6ghz for 5 minutes straight. If I were to do it over I would just buy only the i5 version for my use. I think Intel’s fan algorithm on the i7 is aggressive starting at even low turbo frequency. With the i7 capped at 3.0ghz (to manage fan noise), I ended up paying $100 more than I needed to and got less performance (compared to the i5).