Upcoming Qualcomm Snapdragon 821 will not supplant the Snapdragon 820
Qualcomm has officially announced the new Snapdragon 821 SoC as the newest member of the Snapdragon 800 family. The processor appeared in benchmark databases just a few weeks ago and is intended to bridge the release gap between the Snapdragon 820 and the next eventual "true" successor. Thus, the 821 is not a completely new SoC and is more of a minor update to the Snapdragon 820.
The 821 is almost identical to the 820 including its integrated X12 LTE modem capable of transfer rates of up to 600 MB/s and compatibility with Ultra HD Voice for better call quality. The biggest difference between them will the increase in core clock rate from 2.1 GHz to 2.4 GHz for a claimed performance increase of about 10 percent.
Smartphones with the Snapdragon 821 have not yet been announced, but potential candidates may include the upcoming Nexus smartphones and the Asus Zenfone 3. The current Snapdragon 820 is the powerhouse for most flagship Android devices of 2016 including the HTC 10 and the LG G5. The Exynos 8890, however, carries a measurable lead in raw performance power.