NVIDIA has a new spin on the RTX 4070 graphics card using the AD103 chip rather than the lesser AD104, but it's no different to the latter vanilla model - this is just Team Green repurposing silicon that'd otherwise go to waste.
If you've been following the thread about NVIDIA possibly using different chips for certain models of Lovelace graphics card, it was previously rumored the RTX 4070 would get AD103.
And now that's been confirmed by TechPowerUp, who were contacted by a reader who'd bought an MSI Ventus 3X RTX 4070 graphics card, and found that the GPU-Z utility couldn't detect the GPU correctly.
As TechPowerUp discovered when examining the GPU-Z data provided by the reader, the Ventus board actually used an AD103 chip, hence the failure of the software to successfully identify it. As a result, the utility is being updated to correctly deal with these new AD103-toting RTX 4070 graphics cards.
As you're doubtless aware, what NVIDIA is doing here is taking wonky chips that have failed quality control for the RTX 4080 (or 4070 Ti Super), and disabling cores to bring them down to AD104 level, so they can find a new home as the engine of an RTX 4070.
The RTX 4070 graphics card won't be any better than normal because it's using an AD103 chip instead of AD104 - or it certainly shouldn't be, though there could be very slight differences. (Some argue that a higher-spec chip used in this way may be a touch less power efficient, mind - but any changes aren't going to be noticeable in any real way, positive or negative).