A report from earlier this year said that Google will release two Nexus devices this year, both made by HTC. Now @evleaks has said that those two smartphones are called M1 and S1 internally. Android Police further states that HTC’s internal model numbers are probably based upon the codenames Marlin and Sailfish, named after aquatic life. An earlier rumor revealed different, codenames T50 and T55.
Reference to Marlin is seen in the AOSP Gerrit code review tool last month that confirms the existence of the phone. This is confirmed by senior Qualcomm engineer. Google seems to be testing Snapdragon 820 SoC for its upcoming Nexus device. A Nexus 6P variant with Snapdragon 820, 4GB of RAM and Android N has surfaced on Geekbench with 2115 single-core score and 4903 multi-core benchmark.
Most details of these HTC-made Nexus smartphones are till a mystery. Hope we can expect Google to announce something related to these Nexus smartphones at the Google I/O next month.