Unlike the regular Redmi 1S, the Redmi 1S 4G is powered by 1.3 GHz quad-core MediaTek MT6582 processor with 1 GB of RAM. Note that the Redmi 1S 3G is powered by 1.6 GHz quad-core Qualcomm Snapdragon 400 processor, so you need to think before you pick.
Just like the Redmi Note 4G, the Redmi 1S 4G only supports single-SIM slot. The battery capacity has increased 10% to 2,200 mAh.
Other specs are quite similar - 8 MP camera, 1.6 MP front camera, 4.7" 720p display, 8 GB expandable storage.
The new Redmi 1S 4G is running on MIUI V5 based on Android 4.4 KitKat. However unlike the Redmi Note 4G, the Redmi 1S 4G will be available in China only on 16th August, whilst the Redmi Note 4G will be available in Malaysia by end of this year.