Nvidia on Wednesday revealed the printed circuit board (PCB) design of its GeForce RTX 4090 graphics card and disclosed some of the peculiarities of its new product. As it turns out, the company completely redesigned the card's voltage regulating module (VRM) by adding a PID controller with a feedback loop to ensure proper power supply to the GPU and maximize its overclocking potential.
When fully assembled, Nvidia's GeForce RTX 4090 Founders Edition graphics card resembles its predecessor as it continues to use an extensive dual-fan cooling system featuring a unibody design. But the new product has several distinctive differences outside and, more importantly, inside.
Just like previous generation Founders Edition graphics cards, the new GeForce RTX 4090 FE uses a very sophisticated yet compact PCB with a triangular cut on its back (or its right side, depending on how you look at it) that is meant to maximize the efficiency of Nvidia's flow through thermal design (which is further boosted by bigger fans).
The PCB has a single 12+4-pin 12VHPWR additional PCIe Gen5 power connector that can deliver up to 600W of power to the device, yet default BIOS settings do not allow Nvidia's GeForce RTX 4090 FE to draw more than 450W. The board also comes with a 20+3-phase VRM (20 phases for the GPU, 3 phases for memory), which is a slight improvement from the 18+3-phase power circuitry of the GeForce RTX 3090/3090 Ti FE.
In addition to more power phases, Nvidia implemented a PID controller with a feedback loop to reduce current spikes and drops, effectively stabilizing power delivery to its GeForce RTX 4090 Founders Edition graphics card, reports TechPowerUp. Nvidia says that its new VRM enables a substantially lower power management response time without quantifying it in absolute figures. A stable and clean power supply is crucial for stability under high loads and overclocked conditions. The green company calls this feature 'power transient management,' which might be one of the ways it manages to push its AD102 graphics processor to 3 GHz without overvolting it and using extreme cooling methods.
In addition to enhancing the cooling system with bigger fans that provide up to 20% more airflow and redesigning power delivery, Nvidia also uses new GDDR6X memory chips with its GeForce RTX 4090 FE that consume less power. While we can only speculate how the power consumption of DRAMs featuring PAM-4 signalings was reduced, we suggest that Micron uses a thinner fabrication process to make these chips, which automatically lowers their power consumption. Meanwhile, with colder memory, the cooling system will better cool down the GPU, which means extra overclocking headroom.
Nvidia's GeForce RTX 4090 Founders Edition graphics cards will go on October 12 and will likely join the best graphics cards, at least for those willing to pay $1,599 per unit.