CPU time higher but elapsed time lower when columnstored index used. Wondering why?

I am exploring ColumnStore indexing and comparing with traditional row store.  I wrote two sets of queries doing the same thing - one using columnstore index and the other with primary key clustered and non clustered index. The first one ran three times faster but taking twice cpu time compared to the second one. Wondering why? All the examples I have seen on MSDN show reduced cpu time as well as elapsed time. any explation would be appreciated...

1st query statistics (columnstore index)