SilverStone SX700-G PSU Review: An Overclocked SX650-G?

The powerful SX700-G is based on an enhanced version of SilverStone's SX650-G. It does feature a few component changes. However, we would have liked to see the SX700-G include two EPS connectors, a longer hold-up time, and higher efficiency under light loads.

Apparently, SilverStone wanted to snatch the crown for highest wattage in the SFX category. It took advantage of the fact that Corsair delayed its SF750 to make this happen. But now that the SF750 is available, SilverStone's SX700-G can't touch its competition from Corsair (even though the SF750 is ~$20 more expensive).

If cost is your biggest consideration and Corsair's SFX-based flagship is too expensive, consider the SX650-G over SilverStone's SX700-G. Differences between those two models are minor, and the 650W PSU will save you some money.

As a pioneer in the small form factor power supply business, SilverStone has a rich portfolio of compact PSUs. The brand's primary goal is to shrink its power supplies as much as possible, all while increasing their maximum capacity. The SX700-G is a solid example of its success; we managed to push it beyond 1000W in our tests, despite a 700W maximum power rating. It's noteworthy to see such a small PSU deliver so much power without a problem.

Specifications

Manufacturer (OEM)High Power
Max. DC Output700W
Efficiency80 PLUS Gold, ETA-A (88-91%)
NoiseLAMBDA-S+ (35-40 dB[A])
Modular✓ (Fully)
Intel C6/C7 Power State Support
Operating Temperature (Continuous Full Load)0 - 40°C
Over-Voltage Protection
Under-Voltage Protection
Over-Power Protection
Over-Current (+12V) Protection
Over-Temperature Protection
Short Circuit Protection
Surge Protection
Inrush Current Protection
Fan Failure Protection
No Load Operation
Cooling92mm fluid dynamic bearing fan (S0921512HB)
Semi-Passive Operation
Dimensions (W x H x D)127 x 65 x 103mm
Weight0.94 kg (2.07lb)
Form FactorSFX, EPS 2.92
Warranty3 years

The SX700-G's warranty looks short compared to the seven-year coverage offered by EVGA and Corsair. SilverStone should increase this model's warranty to five years if it wants to give customers more confidence.

Power Specifications

Rail3.3V5V12V5VSB-12V
Max. PowerAmps222258.42.50.3
Watts11070012.53.6
Total Max. Power (W)700

Cables & Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)GaugeIn Cable Capacitors
ATX connector 20+4 pin (300mm)1118-22AWGNo
4+4 pin EPS12V (400mm)1116AWGNo
6+2 pin PCIe (400mm+150mm) 12
16-18AWGNo
6+2 pin PCIe (550mm+150mm) 12
16-18AWGNo
SATA (300mm+200mm+100mm)2618AWGNo
4-pin Molex (300mm+200mm+200mm)1318AWGNo
FDD Adapter (105mm)1122AWGNo
AC Power Cord (1420mm) - C13 coupler1118AWG-

We expected the SX700-G to include two EPS connectors. Unfortunately, SilverStone only arms its 700W PSU with one. The cables are understandably short since SFX PSUs are intended for small enclosures. But the distance between this model's peripheral connectors is ideal at 200mm.

The EPS and PCIe cables use 16-gauge wires for lower voltage drops. And as you can see in the table above, there are no in-cable capacitors to improve ripple filtering.

Component Analysis

General Data
Manufacturer (OEM)High Power
Primary Side
Transient Filter4x Y caps, 2x X caps, 3x CM chokes, 1x MOV, 1x CM02X
Inrush ProtectionNTC Thermistor & Diode
Bridge Rectifier(s)2x GBU1506L (600V, 15A @ 100°C)
APFC MOSFETs2x Infineon IPA50R140CP (550V, 15A @ 150°C, 0.14Ω)
APFC Boost Diode1x Infineon IDH08G65C5 (650V, 8A @ 145°C)
Hold-up Cap(s)1x Rubycon (420V, 470uF, 3000h @ 85°C, USH)
Main Switchers2x Infineon IPA50R140CP (550V, 15A @ 150°C, 0.14Ω)
High-side/Low-Side DriverSilicon Labs Si8233BD
APFC ControllerInfineon ICE3PCS01G
Resonant ControllerChampion CM6901X
TopologyPrimary side: Half-bridge & LLC resonant controller
Secondary side: Synchronous rectification & DC-DC converters
Secondary Side
+12V MOSFETs6x Toshiba TPHR85 04PL (SOP Advance Series, 40V, 150A @ 25C, 0.85mΩ)
5V & 3.3VDC-DC Converters: 6x Infineon BSC0906NS (30V, 40A @ 100°C, 4.5mΩ)
PWM Controller: APW7159C
Filtering CapacitorsElectrolytics: 1x Nippon Chemi-Con (4-10,000 @ 105°C, KY), 4x Rubycon (3-6000 @ 105°C, YXG), 2x Nichicon (4-10,000 @ 105°C, HE)
Polymers: Nippon Chemi-Con
Supervisor ICSITI PS224 (OVP, UVP, OCP,SCP, PG)
Micro ControllerSTC 15W408AS
Fan ModelGlobe Fan S0921512HB (92mm, 12V, 0.45A, fluid dynamic bearing)
5VSB Circuit
Rectifier1x DK5V45R15 SBR (50V, 60A)
Standby PWM ControllerSanken STR-A6069H
-12V Circuit
RectifierKEC KIA7912PI (-12V, 1A)

This is the same platform used for SilverStone's SX650-G with a few component changes allowing for 50W-higher capacity. Although it uses high-quality parts, we'd like to see a better bulk capacitor in the APFC converter. The Rubycon USH line is good enough, but in this price range we're used to finding bulk caps rated for 2000 hours at 105°C. Worse, the bulk cap's capacity is low, preventing it from offering more than 17ms of hold-up time.

The cooling fan is manufactured by Globe Fan. It uses a fluid dynamic bearing, so we know it'll last a long time. While there is no semi-passive mode, this isn't a problem because the fan spins at low speeds under light and moderate loads.

MORE: Best Power Supplies

MORE: How We Test Power Supplies

MORE: All Power Supply Content