GPUs Graphics Reviews

Sapphire Radeon RX 5700 XT Pulse Review – Navi with certain vibrations

Sapphire's first Navi card is with the Pulse actually the entry model, if one follows the previous nomenclature of the manufacturer. This also entails compromises and today we will sound out which and what this means for the customer.

Board layout and components

Sapphire, like AMD, uses a simple 7+2 phase design for the Pulse. The well-known IR 35217 PWM controller from International Rectifier (on the back of the PCB) handles the 7 integrated power stages SiC620A from Vishera for the GPU (VDDC, max. 60 A), which are basically asymmetric dual MOSFETs with an integrated gate driver and a Schottky diode in a common package. For the two phases for the memory (MVDD) Sapphire (like others) relies on an NCP 81022, a digital 2-phase voltage regulator, which drives a slightly smaller SiC232A from Vishera (50 A), which offers lower power, but has a very similar design. These smaller power stages can also be found in the SoC and VDDCI.

Sapphire uses a short PCB with very few active components on the back. A second 8-pin connector would have been possible, but this is an 8+6 combination. One of the VDDC phases for the GPU is fed from the motherboard slot (PEG), the rest via the external PCIe connectors. But we’ll come to balancing later.

Die nachfolgende Tabelle enthält noch einmal die wichtigsten Komponenten:


PWM Controller IR35217
International Rectifier
8-Phasen PWM-Controller (7 genutzt, 3 dazu parallel)
Gate Driver integrated  
VRM 7x SiC620A
Power Stage
Chokes Encapsulated Ferrite Choke
150 mH

Memory and MVDD

Module MT61K256M32
8x 8GB GDDR6 SGRAM-Modules
2 Channels x 256 Meg x 16 I/O, 2 Channels x 512 Meg x 8 I/O
PWM Controller NCP81022
ON Semiconductor
2-Phases used
VRM 2x SiC632A
Power Stage
Spulen Encapsulated Ferrite Choke
330 mH

Other Components

BIOS 25080 CT
Input Filter, Shunts, 560 mH


Features 7 + 2 Phase design
8-Pin + 6-Pin PCI-Express Power Supply



The upper cover carries the two fan modules, each with 9 rotor blades and 9.5 cm diameter (opening 9.8 cm). There are no bigger secrets, but at least the two fans have something acoustic about them, because the speeds differ slightly from each other. But that’s what I’ll explain later in the acoustic measurements.

The GPU cools Sapphire using a simple copper heatsink that is not polished and whose fastenings must support the entire radiator. A total of 5 heatpipes made of nickel-plated copper composite material then distribute the waste heat to the one-piece finned heat sink with the horizontally arranged fins.

The memory and the voltage regulators are cooled by means of a special cooling frame (sandwich design), but one of its special features are the cooling fins mounted at the top, which considerably increase the surface area.

The backplate absorbs the waste heat from the VRM area and is thus integrated into the cooling system. The rest is optical in nature and serves mainly to stabilize the circuit board.


Kühlsystem im Überblick
Cooler: Air Cooling
Heatsink: Copper
Fins: Aluminium, vertikally orientated
Heatpipes 5x 6-mm Heatpipes
VRM Cooling
Cooling Frame
RAM Cooling
Cooling Frame
Fans: 2x 9,5 cm fans, 9 Rotor Blades
Backplate Aluminium
Cooling Function (VRM Backside)