Mariano is right. They aren't the same.
'Sometimes' is an adverb of frequency, like 'always' 'never' and 'usually.' Sometimes has a similar meaning to 'occasionally'. For example. 'I don't always drive to work. Sometimes I walk or cycle.'
'Some times' means 'certain occasions' or 'certain moments' or 'certain periods'. For example, 'There are some times in all our lives when we need our friends and family.'