As the official launch of the NVIDIA RTX 4090 and its custom versions approaches, photos of its gigantic motherboard have been appearing. The already large 4090 Founders Edition are outclassed by GPUs from Nvidia's partners.
This has a good explanation, if its veracity is confirmed. According to Igor's Lab, the partners were only following orders from Nvidia, which passed them outdated plans before going into production, with plans changed at the last minute.
A last minute change for the NVIDIA RTX 4090
The German overclocker claims that his information is based on sources from the AIB supply chain for NVIDIA partners in Taiwan. The design of GPUs, and their coolers, is a very long process and therefore information is given months in advance that cannot be easily changed. Nvidia had originally ordered its partners to prepare 600W coolers for its upcoming GPUs, and when this order was given, Nvidia planned to reuse Samsung silicon for Ada Lovelace. The instructions were included in the Thermal Design Guide that Nvidia sent out to its partners.
Nvidia figured it would need 600W of power to hit the necessary clock speeds to boost performance if it used Samsung's process. But Nvidia switched to TSMC's 4nm node quickly. This change offered better performance, and allowed reduce the total power of the board from 600 W to 450 W, the same TBP as that of the RTX 3090 Ti. The consumption of the 4080 GB RTX 16 has also been drastically reduced, from 420 W to about 320 W.
This would explain the enormous size that it has, despite the fact that it does not correspond to its final power, and the rumors that we have been receiving since April of its enormous energy cost. It was speculated that would need two PCIe Gen5 power connectors, but in the end you only need one.
The last-minute change upset Nvidia's partners, who had to do unnecessary engineering, plus the boards cost $10 more than normal, hurting profit margins. May well be one of the reasons why EVGA has decided to leave its GPU business.
Nvidia's design has three slots, most AIB designs are even larger. This should allow for very low temperatures and high clock speeds. According to Wccftech, the RTX 4090 runs at a temperature between 50º C and 55º C with clock speeds above 2,8 GHz. It can also reach 3 GHz if overclocked. But your biggest hurdle will be the voltage.
