You need a rooted device for that, and then you can install no frills CPU tool which tells you all that, and lets you over clock if you have an overclocking kernel installed.
Samsung Galaxy S3 (Stock, rooted TouchWiz)
Samsung Galaxy Tab 3 7.0 (non-rooted, stock)
Samsung Galaxy Tab 2 10.1 (obsolete, slow, rooted)
Samsung Galaxy Note 10.1 2014 Edition