AMD Radeon RX 7900 XTX Reference Design PCB and Cooler Detailed
AMD Radeon RX 7900 XTX reference-design isn't a first-party product with limited availability like the NVIDIA Founders Edition; but rather a classic reference-design that's sold by AMD's add-in board partners under their marquee (without sticking their own labels on the product). AMD and its partners internally refer to reference-design cards as "MBA cards" (made by AMD cards). The company gave us a technical overview of the reference-design PCB. As with every reference AMD PCB for the past several generations, the RX 7900 XTX PCB has a premium selection of components. The card uses an expensive 14-layer PCB with 4 additional layers of 2-oz copper. 14-layer PCBs are typically used with enterprise-grade products, and graphics cards typically tend to have PCB layer counts of around 10. The PCB also uses ITEQ IT-170GRA epoxy and laminate materials, which enable a glass transition temperature (Tg) of 175 °C (no, the GPU won't get anywhere near as hot).
The reference-design RX 7900 XTX PCB draws power from two 8-pin PCIe power connectors. With the typical board power of the RX 7900 XTX rated at 355 W, this falls inside the 375 total power-draw capability when you add up the 150 W input from the two connectors, and 75 W from the PCIe slot. AMD worked to minimize power-draw spikes at least from the PCIe slot. Excursions, if any, should be localized to the 8-pin power connectors. The card features 20-phase VRM solution, using "high efficiency" DrMOS power-stage phases (could be very high current). The "Navi 31" GPU is surrounded by 12 GDDR6 memory chips given the GPU's 384-bit memory interface. Two of these memory pads could end up unused on the RX 7900 XT, which has a 320-bit memory interface. Display outputs of the RX 7900 series include two standard-size DisplayPort 2.1, one USB type-C with DisplayPort passthrough; and one HDMI 2.1a.
The reference-design RX 7900 XTX PCB draws power from two 8-pin PCIe power connectors. With the typical board power of the RX 7900 XTX rated at 355 W, this falls inside the 375 total power-draw capability when you add up the 150 W input from the two connectors, and 75 W from the PCIe slot. AMD worked to minimize power-draw spikes at least from the PCIe slot. Excursions, if any, should be localized to the 8-pin power connectors. The card features 20-phase VRM solution, using "high efficiency" DrMOS power-stage phases (could be very high current). The "Navi 31" GPU is surrounded by 12 GDDR6 memory chips given the GPU's 384-bit memory interface. Two of these memory pads could end up unused on the RX 7900 XT, which has a 320-bit memory interface. Display outputs of the RX 7900 series include two standard-size DisplayPort 2.1, one USB type-C with DisplayPort passthrough; and one HDMI 2.1a.