Sentey SDP850-SS Power Supply Review

[nextpage title=”Introduction”]

The Sentey Solid Power SS series of power supplies has 550 W, 650 W, 750 W, and 850 W models, all with the standard 80 Plus certification. Today we are going to dissect the 850 W model (SDP850-SS), which uses a resonant configuration in its primary and DC-DC and synchronous designs in its secondary, features that are usually only seen on high-efficiency power supplies with at least the 80 Plus Bronze certification. Let’s see if we were surprised by this product.

The Sentey SDP850-SS is a rebranded Super Flower SF-850P14HE power supply.

Figure 1: Sentey SDP850-SS power supply

Figure 2: Sentey SDP850-SS power supply

The Sentey SDP850-SS is 7.1” (180 mm) deep. It uses an unidentified 140 mm fan on its bottom.

Figure 3: Fan

This power does not have a modular cabling system. All cables have individual nylon sleeves. This power supply comes with the following cables:

• Main motherboard cable with a 20/24-pin connector, 20.1” (51 cm) long
• One cable with two ATX12V connectors that together form an EPS12V connector, 22” (56 cm) long
• Two cables, each with one six-pin connector and one six/eight-pin connector for video cards, 18.9” (48 cm) to the first connector, 5.1” (13 cm) between connectors
• Two cables, each with four SATA power connectors, 18.9” (48 cm) to the first connector, 5.1” (13 cm) between connectors
• One cable with three peripheral power connectors, 19.3” (49 cm) to the first connector, 5.1” (13 cm) between connectors
• One cable with two peripheral power connectors and one floppy disk drive power connector, 19.3” (49 cm) to the first connector, 5.1” (13 cm) between connectors

All wires are 18 AWG, which is the minimum recommended gauge, except for the +12 V (yellow) wires on the main motherboard cable, which are thicker (16 AWG).

This is a somewhat standard configuration for mainstream 850 W units.

Figure 4: Cables

Let’s now take an in-depth look inside this power supply.

[nextpage title=”A Look Inside the Sentey SDP850-SS”]

We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our “Anatomy of Switching Power Supplies” tutorial to understand how a power supply works and to compare this power supply to others.

On this page we will have an overall look, and then, in the following pages, we will discuss in detail the quality and ratings of the components used.

Figure 5: Top view

Figure 6: Front quarter view

Figure 7: Rear quarter view

Figure 8: The printed circuit board

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we look at when opening a power supply for a hint about its quality is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil.

In the transient filtering stage, this power supply has all required components, except for the MOV, which is in charge of removing spikes coming from the power grid. Interesting enough, there is a place reserved for an MOV on the printed circuit board.

Figure 9: Transient filtering stage

On the next page, we will have a more detailed discussion of the components used in the Sentey SDP850-SS.

[nextpage title=”Primary Analysis”]

On this page, we will take an in-depth look at the primary stage of the Sentey SDP850-SS. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses one GBU1506 rectifying bridge, which is attached to the same heatsink as the primary transistors, but it is also attached to an individual heatsink. This bridge supports up to 15 A at 100° C if a heatsink is used, which is the case here. In theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 W without burning itself. Of course, we are only talking about this component. The real limit will depend on all the other components in this power supply.

Figure 10: Rectifying bridge

The active PFC circuit uses two IPP50R199CP MOSFETs, each one supporting up to 17 A at 25° C or 11 A at 100° C in continuous mode (note the difference temperature makes), or 40 A at 25° C in pulse mode. These transistors present a 199 mΩ maximum resistance when turned on, a characteristic called RDS(on). The lower the number, the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.

The active PFC circuit is controlled by an NCP1653A integrated circuit.

Figure 11: Active PFC controller

The output of the active PFC circuit is filtered by one 680 μF x 420 V electrolytic capacitor from CapXon, labeled at 85° C.

Figure 12: Capacitor

This power supply uses a resonant configuration with another two IPP50R199CP MOSFETs. The specifications for these transistors were already discussed above.

Figure 13: The two switching transistors, the active PFC diode, and one of the active PFC transistors

The switching transistors are controlled by a custom-made resonant controller called SF29601, which is physically located in the secondary. Since this is a custom integrated circuit, no datasheet is available for it.

Figure 14: Resonant controller

Let’s now take a look at the secondary of this power supply.

[nextpage title=”Secondary Analysis”]

Even though Sentey officially sells the SD850-SS as having the standard 80 Plus certification, it uses a synchronous design, where the Schottky rectifiers are replaced with MOSFETs, and a DC-DC design, which means that the power supply is basically a +12 V unit, with the +5 V and +3.3 V outputs produced by two smaller power supplies connected to the main +12 V rail. Both designs are used to increase efficiency, and are usually only seen on high-efficiency power supplies with at least the 80 Plus Bronze certification.

The +12 V output uses four IPP040N06N MOSFETs, each one supporting up to 80 A at 100° C in continuous mode, or up to 320 A at 25° C in pulse mode, with a maximum RDS(on) of 4 mΩ.

Figure 15: The +12 V transistors

As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters, which are located on a single printed circuit board located in the secondary section of the power supply. Each converter is controlled by one NCP1587A integrated circuit and uses two IPD060N03L MOSFETs, which support up to 50 A at 100° C in continuous mode and up to 43 A at 25° C in pulse mode, with a maximum RDS(on) of 6 mΩ.

Figure 16: The DC-DC converters

Figure 17: The DC-DC converters

We did not see an integrated circuit for monitoring the power supply outputs. Since the Power Good wire and sensors were connected to the small printed circuit board where the resonant controller was attached, our best guess is that the enigmatic SF29601 controller, with the aid of four operational amplifiers provided by an LM324 integrated circuit, does the trick.

The electrolytic capacitors available in the secondary are also from CapXon and labeled at 105° C, except for the electrolytic capacitor used on the +5VSB output, which is from Su’scon.

Figure 18: Capacitors

[nextpage title=”Power Distribution”]

In Figure 19, you can see the power supply label containing all the power specs.

Figure 19: Power supply label

This power supply has a single +12 V rail, so there is not much to talk about here.

Let’s find out how much power this unit can deliver.

[nextpage title=”Load Tests”]

We conducted several tests with this power supply, as described in the article “Hardware Secrets Power Supply Test Methodology.”       

First, we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.

If you add all the powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (e.g., the +5 V output working at 5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.

The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test, the +12VA and the +12VB inputs were connected to the power supply’s single +12 V rail (the +12VB input was connected to one of the power supply’s EPS12V connectors).

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	6 A (72 W)	13 A (156 W)	19 A (228 W)	25.5 A (306 W)	32 A (384 W)
+12VB	6 A (72 W)	13 A (156 W)	19 A (228 W)	25.5 A (306 W)	31.5 A (378 W)
+5 V	1 A (5 W)	2 A (10 W)	4 A (20 W)	6 A (30 W)	8 A (40 W)
+3.3 V	1 A (3.3 W)	2 A (6.6 W)	4 A (13.2 W)	6 A (19.8 W)	8 A (26.4 W)
+5VSB	1 A (5 W)	1.5 A (7.5 W)	2 A (10 W)	2.5 A (12.5 W)	3 A (15 W)
-12 V	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)
Total	165.4 W	345.0 W	507.8 W	680.9 W	851.4 W
% Max Load	19.5%	40.6%	59.7%	80.1%	100.2%
Room Temp.	44.5° C	44.6° C	44.8° C	46.7° C	49.8° C
PSU Temp.	48.6° C	46.1° C	45.5° C	48.5° C	50.6° C
Voltage Regulation	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	188.8 W	388.3 W	576.0 W	788.0 W	1011.0 W
Efficiency	87.6%	88.8%	88.2%	86.4%	84.2%
AC Voltage	116.9 V	114.9 V	112.4 V	109.6 V	107.3 V
Power Factor	0.977	0.989	0.992	0.994	0.994
Final Result	Pass	Pass	Pass	Pass	Pass

The efficiency results for this power supply were simply amazing, at the levels required for the 80 Plus Silver certification (88% minimum efficiency at 50% load and 85% minimum efficiency at 20% and 100% loads), except on the full load test. Sentey could easily get this power supply certified as 80 Plus Bronze. Yet, for some unknown reason, this power supply is labeled as having the standard 80 Plus certification. We honestly believe that this was a mistake done by Sentey.

Let’s discuss voltage regulation on the next page.

[nextpage title=”Voltage Regulation Tests”]

The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values. We consider a power supply as “flawless” if it shows voltages within 3% of their nominal values. In the table below, you can see the power supply voltages during our tests and, in the following table, the deviation, in percentage, of their nominal values.

The Sentey SDP850-SS presented excellent voltage regulation, with all outputs within 3% of their nominal values, except for the +5 V output during test one and the +3.3 V output during test five.

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	+12.16 V	+12.12 V	+12.08 V	+12.04 V	+12.02 V
+12VB	+12.15 V	+12.08 V	+12.01 V	+11.96 V	+11.91 V
+5 V	+5.17 V	+5.14 V	+5.10 V	+5.07 V	+5.04 V
+3.3 V	+3.33 V	+3.29 V	+3.26 V	+3.24 V	+3.20 V
+5VSB	+5.08 V	+5.06 V	+5.02 V	+4.99 V	+4.96 V
-12 V	-12.08 V	-12.10 V	-12.11 V	-12.14 V	-12.16 V

 

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	1.33%	1.00%	0.67%	0.33%	0.17%
+12VB	1.25%	0.67%	0.08%	-0.33%	-0.75%
+5 V	3.40%	2.80%	2.00%	1.40%	0.80%
+3.3 V	0.91%	-0.30%	-1.21%	-1.82%	-3.03%
+5VSB	1.60%	1.20%	0.40%	-0.20%	-0.80%
-12 V	-0.67%	-0.83%	-0.92%	-1.17%	-1.33%

Let’s discuss the ripple and noise levels on the next page.

[nextpage title=”Ripple and Noise Tests”]

Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple”). The maximum ripple and noise levels allowed are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.

The Sentey SDP850-SS provided low ripple and noise levels, making it a “flawless” unit on this test.

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	12.4 mV	18.2 mV	25.8 mV	41.8 mV	48.8 mV
+12VB	12.8 mV	19.8 mV	26.4 mV	58.2 mV	46.2 mV
+5 V	6.6 mV	8.8 mV	11.0 mV	24.2 mV	19.8 mV
+3.3 V	5.0 mV	8.2 mV	11.2 mV	39.4 mV	24.2 mV
+5VSB	6.4 mV	8.4 mV	12.6 mV	31.8 mV	22.4 mV
-12 V	8.8 mV	10.8 mV	15.0 mV	35.2 mV	23.6 mV

 

Below you can see the waveforms of the outputs during test five.

Figure 20: +12VA input from load tester during test five at 851.4 W (48.8 mV)

Figure 21: +12VB input from load tester during test five at 851.4 W (46.2 mV)

Figure 22: +5V rail during test five at 851.4 W (19.8 mV)

Figure 23: +3.3 V rail during test five at 851.4 W (24.2 mV)

Let’s see if we can pull more than 850 W from this unit.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. The objective of this test is to see if the power supply has its protection circuits working properly. This unit passed this test, since it shut down when we tried to pull more than what is listed below. During this test, noise and ripple levels were still relatively low and voltages were within 3% of their nominal values, except for the +3.3 V output, which was still inside the allowed range, though.

Input	Overload Test
+12VA	33 A (396 W)
+12VB	33 A (396 W)
+5 V	20 A (100 W)
+3.3 V	20 A (66 W)
+5VSB	3 A (15 W)
-12 V	0.5 A (6 W)
Total	970.8 W
% Max Load	114.2%
Room Temp.	48.8° C
PSU Temp.	47.9° C
AC Power	1,227 W
Efficiency	79.1%
AC Voltage	103.5 V
Power Factor	0.995

[nextpage title=”Main Specifications”]

The main specifications for the Sentey SDP850-SS power supply include:

• Standards: ATX12V 2.2 and EPS12V 2.92
• Nominal labeled power: 850 W
• Measured maximum power: 970.8 W at 48.8° C
• Labeled efficiency: Above 80%, standard 80 Plus certification
• Measured efficiency: Between 84.2% and 88.8% at 115 V (nominal, see complete results for actual voltage)
• Active PFC: Yes
• Modular Cabling System: No
• Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector
• Video Card Power Connectors: Two six-pin connectors and two six/eight-pin connectors on two cables
• SATA Power Connectors: Eight on two cables
• Peripheral Power Connectors: Five on two cables
• Floppy Disk Drive Power Connectors: One
• Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over power (OPP), and short-circuit (SCP)
• Are the above protections really available? Yes.
• Warranty: Five Years
• Real Model: Super Flower SF-850P14HE
• More Information: https://www.sentey.com
• Average Price in the U.S.*: USD 110.00

* Researched at Amazon.com on the day we published this review.

[nextpage title=”Conclusions”]

The Sentey SDP850-SS is a rare case where the power supply was under labeled. It is sold as having the standard 80 Plus certification, but the manufacturer could easily achieve the 80 Plus Bronze certification, as efficiency was practically within 80 Plus Silver numbers. This happened because the Sentey SDP850-SS uses resonant, DC-DC, and synchronous designs, features that are usually only available in high-efficiency power supplies with at least the 80 Plus Bronze certification.

Our results are compatible with the design used by the power supply, however way above the numbers present in the 80 Plus certification report for this unit. The only explanation we have is that Super Flower changed the platform used in this power supply and decided to not re-certify the unit. (When power supplies are rebranded models, they are not retested: the 80 Plus report is the same as the original unit, only with the title changed.)

As a standard 80 Plus power supply, the price for the SDP850-SS seems a bit high. However, knowing that for loads up to 80% it can achieve efficiency comparable to 80 Plus Silver products, it is a bargain. Therefore, the Sentey SDP850-SS is a terrific power supply if you know what you are taking home.

Voltage regulation and noise levels were good for a mainstream power supply.