It's impossible to tell which kind of CPU DOSBox emulates at a certain cycle rate. It very much depends on the game you want to run.
On my Athlon XP 1800+ I can run Ultima Underworld perfectly well at 10000 cycles, but only at the approximate speed of my old 386/33. On the other hand, Warcraft 2 or Comanche run much faster in comparison (my guess: ~486/50 MHz).
CBench (http://www.intelligentfirm.com/bench.htm) rates DOSBox (10000 cycles) nearly as fast as a Pentium-166, but only because it provides an excellent video speed (4x the speed of a Pentium-200). Still, its real performance is rated significantly better than that of a 486-33:
Pentium-100: 1.31
DOSBox (10000 cycles): 4.60
TOSHIBA 486-33: 6.07
Although these results show how unreliable benchmark results for DOSBox are, you still get a rough idea of its performance.
I think that, if you're planning to upgrade your CPU in the future, you might be able to emulate something like a Pentium/60 and play Magic Carpet well enough (P4HT/3,2 or even better Athlon64 FX 😁!!!).