Even though the leaker now claims the manufacturer told him the PCB is for an RTX 3080 card, we can definitely spot a few elements that seem a bit overkill for an xx80 model: 11 memory modules for at least 22 GB of VRAM, triple 8-pin power connectors plus a hidden special chip on the back of the PCB. Micron, on the other hand, confirms that the RTX 3090 is indeed real and it will integrate the new 21 Gbps GDDR6X modules with 1 TB/s bandwidth.
https://www.notebookcheck.net/Leaker-shows-alleged-Nvidia-RTX-3090-PCB-later-rectifies-it-is-just-for-an-RTX-3080-card-while-Micron-confirms-existence-of-flagship-RTX-3090-with-GDDR6X-memory.486170.0.html