In zenfone 3 4gb variant(ze552kl)..total available ram 3.5 gb..but in mobile manager or clear something it shows maximum 2gb ram..just it say <2gb available...but other 4gb smart phones ram always available greater than 2 gb..but in zenfone 3 its not..i can not find out why it happend .the availability of ram is too poor..but still the total usable ram is 3.5gb..aren't all of you facing it??all of you agree with me??