Tear Down and Board Analysis
MSI relies on its own design for this card, now even in revision 4. However, this also means that it is not a new development based on the PG161 layout, which Nvidia specifies for the RTX 2060 in the "Base Design Kit" and which relies on a 6-layer board. On the 8-layer board used in the PG160 layout you could also easily add a voltage converter phase for the GPU, but that's exactly what you save. No special feature in this power class is the single 8-pin ATX power supply connection.
The two 12V rails (i.e. also the power supply from the motherboard slot) were each equipped with a 330 mH coil (ATX) and a 1H coil (PEG) for the smoothing of possible spikes and each carry out its own shunt for the monitoring of the current flow. In addition, MSI also installs fuses for each power rail.
Let's start with phase splitting. An On Semiconductor (On Semi) NCP81610 Multi-Phase Buck Controller takes on the task of the PWM controller, which is specifically designed to provide high-precision output voltage systems for the latest generation of GPUs. It supports NVIDIA Open Voltage Regulator Type 4i+ with PWMVID function. The integrated SMBus interface offers enough flexibility to optimize performance and efficiency and also to connect the appropriate software.
The NCP81610 delivers the 5 phases for the GPU, which use an NCP81158 (Synchronous Buck MOSFET Driver) to control two FDPC5018SG (Asymmetric Dual N-Channel PowerTrench Power Clip MOSFET) each time (both from On Semi). These dual MOSFETS combine the MOSFET for the high and low-side and the Schottky diode in one package. Thus, the GPU can fall back on a total of 5 phases, in which a potent dual MOSFET pair works in parallel in order to split the currents on a parity basis.
The memory modules are supplied via two phases, with the task of the PWM controller being a uP1660Q from UPI Semiconductor. Since significantly less power is required here, as only six instead of eight memory modules are installed, a dual MOSFET per phase is sufficient. And you can see again very clearly that it is not a special and exclusive board for the GeForce RTX 2060 and you can only realize the saving effect by omitting some components
The omission of phases (e.g. only 5 instead of 6), but also causes various problems with balancing, which requires a very sensitive fine tuning in order to avoid exactly these. I had already explained balancing in my article "When the editor becomes a developer", including possible uncertainties and causes of an imbalance. In contrast to the larger cards, this board does not rely on the Smart Power Stages (PLC), but on the described solution of individual components.
Keyword DCR (Direct Current Resistance). This is the basis for calculating the flowing currents. But how does the controller learn exactly which currents flow in which control loop? The PLC supply the so-called MOSFET DCR, in the here available, rather simple circuit, one relies on the Inductor DCR, i.e. a current measurement via the inductive resistance of the respective filter coils in the output range. The accuracy of this solution is also strongly influenced by fluctuations in the quality of the components.
So if you simply owe away a phase with such a design, you have to distribute the load among fewer phases. It must also be taken into account that one of the phases is fed from the motherboard slot and that this is limited to a maximum of 5.5 amperes at the permissible current from the house. MSI has been able to better balance this imbalance in retail cards, so that everything is now in the green area in terms of cooling. But that comes a little further back in the review.
Cooler and backplate in detail
In the photos you can see that MSI (again) works with partially covering mounting frames on the top of the board, where the larger one should cool the memory. The voltage converters are cooled separately via another, smaller cooling frame. Both serve as a counterpart for the screwing the backplate.
In contrast to the pre-sent MVT cards for the press, the left pad of the smaller frame (responsible for the VRMs) has been significantly upgraded in the series and has a 50% higher thermal conductivity. The rest, as usual, consists of the usual suspects.
Four 6 mm heatpipes distribute the waste heat to the cooling fins. This time, MSI uses a common fan arrangement with two adjacent 8.5cm fans above the two halves of the cooling blocks. We can see how well this works. The heat sink made of light metal carries the four threaded sleeves with which the cooler is attached.
In contrast to the MVT cards in the series, the brushed backplate made of aluminium now also cools the MOSFETS on the rear via thermal guide pads. The picture shows the reconstruction, which later served as a blueprint for mass production:
Cooling system at a glance | |
---|---|
Type of cooler: | Air |
Heatsink: | Nickel-plated heatsink, GPU |
Cooling fins: | Aluminum, horizontal alignment related |
Heatpipes | 4x 6 mm, nickel-plated copper composite |
VRM cooling: | 10 GPU VRM via built-in heat sink 2 Memory VRM via built-in heat sink |
RAM cooling | via mounting frame |
Fan: | 2x 8.5 cm fan, 14 rotor blades semi-passive lyrised |
Backplate | Aluminum Cooling function |
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