Samsung: No KitKat update for international Galaxy S3 and S3 Mini
Most versions of the Samsung Galaxy S3 won't be getting the upgrade to KitKat. The LTE version of the S3, however, will be eligible for the Android 4.4 upgrade.
However, Samsung has said the KitKat update will be made available for the Galaxy S3 LTE, which sports 2GB of RAM.
Interestingly, KitKat does run on phones with only 512MB of RAM, and KitKat is present on newer phones such as the Galaxy Ace Style which has 512MB RAM.