Board design
Even with this card, gigabytes rely on a rather elaborate 6+1 phase design, in which the 6 GPU phases (VDDCR_GFX) each control loop. This task is done by the IR 35271 from International Rectifier, which controls the discretevoltage converters via special gate drivers. Each of the VDDCR control circuits has one AON6414A as high-side MOSFET and two parallel AON6354 on the low side, all three from Alpha & Omega. This is then smoothed with a rather small 150 nH coil. In addition, there is a similar control circuit for the SoC with identical semiconductor assembly, but with 360 nH smoothing coil.
The memory (MVDD) is supplied with only a stronger phase, which is generated by an ON Semi NCP 81022N. An AON6414A on the high side and a single AON6354 on the low-side with a 360 nH coil for smoothing are then used again as voltage converters. Micron's four 14 Gbps 2GB memory modules are then connected to this single phase and, on balance, even more efficient than eight individual 1GB modules. The 8-pin connection is not secured, a smoothing coil is then found a little further away in the supply line to the voltage converters. The division of the GPU voltage converters into discrete components instead of DrMOS is likely to have been done here for cost reasons. However, this also suffers a little from the efficiency of the converter circles, but as a gift.
An ARM controller from Holtek takes over the control tasks. On the back there are few active components, which include the voltage converters for various partial voltages, but also the BIOS near the socket.
Here is a summary of the most important components:
Cooler design
Two non-nickel-plated 6 mm copper composite heatpipes embedded in an aluminum heatsink (which also cools the memory) connect the GPU block to the two other cooling blocks, one carrying the built-in heatsink for the voltage converters. The three small 7.5 cm fans are more or less responsible for one of these blocks, all of which are arranged vertically.
The voltage converters are thus cooled via a separate heat sink anchored in the cooler. This is exemplary and can be seen later in the temperatures. The backplate made of simple ABS injection moulding is purely optical in nature and cannot be included in the cooling concept.
Fan | 3x 7.5 cm rotor diameter 11 rotor blades Turbulence, throughput |
Cooling fins | Vertically |
GPU Cooling | DHT, Alu-Heatsink / Base Plate |
Memory cooling | Common base plate |
VRM cooling | Own heatsink in the cooler |
Pads | 0.5 mm (memory), 1 mm VRM |
Fan operation | Semi-passive mode, fan stop |
GIGABYTE Radeon RX 5500 XT Gaming OC 8G, 8GB GDDR6, HDMI, 3x DP (GV-R55XTGAMING OC-8GD)
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