I have noticed lately that DOSBox seems to be pushing one of my CPU's cores to the limit. This is undesirable because it generates heat and uses power.

Even with cycles set to 1 and frameskip to 60, DOSBox *still* uses nearly 100% of the CPU core. Any idea why this might be?

(Note that these settings aren't really usable for actual gaming; Bard's Tale 1 didn't start in a reasonable amount of time, and 60 frameskip means it can take as much as a second for the video to respond. I just use these settings because they should, in theory, reduce the CPU usage to close to 0.)

You have a very tasty looking CPU.

Although, question, what kind of processor do you even have?

Yes, but at the settings I used for testing (1 cycle, 1 frame displayed per second) it really shouldn't be eating much CPU. I could understand if this happened at 30000 cycles and 0 frameskip (the settings I'm using for Arena, which runs smoothly), but at 1 cycle and 60 frameskip, it really should be using almost no CPU.

I'm no expert on DOSBox but it could be binding the resources preemptively.

Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz

(According to lscpu)

I have not checked DOSBOX CPU usage on my laptop, which has a Celeron as its CPU and is fanless.

So you've been using fixed cycles count. Have you tried max cycles set to a lower percentage?

My assumption was correct.
http://sirian.warpcore.org/moo1/dosbox.html
See Step 3.
From what I understand, the more of your actual CPU DOSBox is using at all times, the better the emulated CPU runs.