Pentiums rhymes with:
abiam's, aquariums, atriums, auditoriums, axioms, caladiums, condominiums, consortium's, geraniums, gymnasiums, herbariums, honorariums, idioms, mediums, millenniums, moratoriums, petroleum's, podiums, premiums, stadium's, stadiums, symposiums, wiliams, zirconiums
Pentiums sounds like:
painting, paintings, pandanus, pandemic, panting, pending, phantoms, pointing, pontoons, pounding