The fake GPU die copied the labelling, package, chip markings and even the compound around the processor, and it was soldered on with a ball grid array so it looked factory-fitted. It was not perfect: the substrate colour, surface reflections and some lettering gave it away, and once the package came off, the contact area bore no resemblance to a working processor while the solder mask deteriorated during cleaning.

The memory was subtler still. The chips looked genuine and closely mimicked Micron's markings, but removing one revealed GDDR6 memory rather than the GDDR6X that a real RTX 4090 uses. VIK-off suspects the PCB design may be based on an RTX 3090 Ti, though there is no conclusive proof.

Counterfeit 4090s are not new. In June, Chinese shop owner Brother Zhang found a broken card bought for around $222 that carried a plastic imitation of Nvidia's AD102 die, complete with a "TW 3043E2" marking implying it was manufactured in 2030. The lesson stands: treat untested high-end cards with suspicion, ask for proof they work and test one in a system before paying.