AMD Radeon RX 7800 XT & RX 7700 XT Performance, Power Analysis & Noise Output

Part Analysis

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Taking apart AMD’s reference card is not hard. The metallic backplate protects the card while helps in lowering its operating temperatures. Since I had limited time to deliver this review on time, I will only analyze the RX 7800 XT. The RX 7700 XT’s design is similar, though.

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The black heatsink has four heatpipes, and its plate looks to be made of copper for better heat handling. The blue padding is of good quality, ensuring good heat transfer. It reminds me of the PUTTY 607 that XBOX uses.

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Photos of the PCB’s front and back sides.

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The Navi 32 GPU. TSMC Taiwan makes it using a 5-nanometer process. It has a die size of 350 mm², enough to host 28.1 billion transistors.

The GPU (VDDCR_GFX) is powered through eight power phases, while two power phases handle the VDD_SOC. The RX 7700 XT PCB’s main difference is that it has one VDDCR_GFX less.

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Monolithic Power Systems (MPS) provides the monolithic ICs handling all power phases, and their model time is MP86957. Each can handle up to 70A, and the maximum switching frequency reaches 3 MHz. The VDDC_GFX controller is an MP2853, which supports up to six phases in total, so it has to have some help to control all power phases. The RAM’s voltage controller is a Monolithic Power Systems MP2856 controller. Another M2856 controller handles VDDC_SOC and VDDCR_USR.

The Hynix GDDR6 RAM chips can do 2500 MHz (20Gbps effective), and their model number is H56G42AS8DX-014.

The pair of cooling fans and their frame. The cooling fans are by Delta Electronics, and their model number is AUB0812VD-00.

Power Scheme Front

Power Scheme Rear

My friend Igor (Igor’s Labs) was kind enough to share with me the 7800 XT’s PCB layout.