$142 upgrade kit and spare modules turn Nvidia RTX 4090 24GB to 48GB AI card — technician explains how Chinese factories turn gaming flagships into highly desirable AI GPUs

Chinese factories are upgrading Nvidia's GeForce RTX 4090 24GB graphics card to 48GB for AI workloads using a $142 "upgrade kit" with a custom PCB and additional memory chips. A technician demonstrated the process of doubling the memory capacity by soldering components onto the PCB. Modified firmware is also uploaded to enable the expanded memory. The total cost for the upgrade is around $430, offering a 39% savings compared to buying a pre-upgraded card. With RTX 4090 supply decreasing, factories may soon turn to upgrading the RTX 5090, potentially leading to even higher memory configurations like the rumored 128GB RTX 5090.