The rumour was started by leaker Roland Quandt who based his theory on a comment made by a Qualcomm contractor who claimed to be working on just such a chip.
While most had expected the Samsung Galaxy S10 to have a Snapdragon 855 as that’s likely to be Qualcomm’s top-end chipset at the time, but what is worth highlighting it is going to be 7nm.
This would be smaller than the 10nm Snapdragon 845 destined for the Galaxy S9, which could allow for both improved performance and better efficiency, meaning it will be more powerful but also last longer.
This would probably be Qualcomm’s first 7nm chipset and one of the first from any manufacturer.
Quandt further notes that the chipset will probably use Qualcomm’s X24 modem, and that’s important too, as it supports theoretical download speeds of up to 2Gbps, up from the 1.2Gbps max of the X20 modem in the Snapdragon 845.
It will probably only be the US and China that gets this chip in the Galaxy S10, with other regions likely getting an Exynos chipset, and we don’t know what its superpower is yet.