Silverstone SX500-LG 500w SFX-L Power Supply Overview

Silverstone SX500-LG 500w SFX-L Power Supply Overview 9


Brand: Silverstone
Model: SX500-LG 500w SFX-L
Price: £68.32 @Amazon UK (At time of review)

It’s no secret that technology is becoming smaller and smaller as years go by. We just have to look at how mobile phones, televisions and even PC cases have changed to see the current trends; maybe not televisions, they are getting bigger! One thing however which has the need to shrink somewhat is power supplies as ITX and small form factor cases are now a thing, but not just that, they are crazily popular among enthusiasts and consumers alike. The need for smaller power supplies is one thing, but the need for a “quality” one is another task as graphics cards companies such as AMD are releasing NANO versions of their flagship cards; something a tin pot firework for a power supply certainly won’t be able to handle.

Enter Silverstone with their SX500-LG 500w SFF 80PLUS Gold rated power supply and oh boy is it well received. Not only does it encompass Silverstone’s quality in a smaller size, but it comes built upon a single 12v 40A rail which is surely going to please aficionado and enthusiasts looking for “quality” over size. Most SFF form factor power supplies are limited to an 80mm fan due to size, but Silverstone have pushed the boundary and added in a full size 120mm fan designed to provide optimal cooling performance while operating at low noise levels.


Model No.
Max. DC Output
Power density
484W per liter
Load Range
+3.3V +5V +12V +5VSB -12V
20A 20A 40A 3.0A 0.3A
Peak (Amps)
/ / / / /
0A 0A 0A 0A 0A
Range (%)
±3% ±3% ±3% ±5% ±10%
Line Reg.(%)
±1% ±1% ±1% ±1% ±2%
50mA 50mA 120mV 50mV 120mV
Black(Lead-Free Paint)
combined +3.3, +5V
combined +12V
Input Voltage
90V ~ 264V
Input Frequency Range
47Hz ~ 63Hz
Active PFC(PF>0.95 at full load)
87%~90%(20% to 100% loading)
100,000 hours
Operating temperature
0°C ~ 40°C
Over Power Protection
Over Voltage Protection
Over Temperature Protection
Under voltage protection
Short Circuit Protection
1 x 24 / 20-Pin motherboard connector(300mm)
1 x 8 / 4-Pin EPS / ATX 12V connector(400mm)
2 x 8 / 6-Pin PCIE connector(400mm / 150mm)
3 x SATA connector(300mm / 200mm / 100mm)
2 x 4-Pin Peripheral connector (300mm / 200mm)
1 x 4-Pin Floppy connector(300mm / 200mm / 200mm)
Cooling System
Single 120mm silent fan
Noise Level
0 ~ 36 dBA
125 mm (W) × 63.5 mm (H) × 130 mm (D)
1.4 Kg
Form factor
80 PLUS Gold
Includes SFX to ATX bracket for use in ATX case
GPU Support list
Haswell CPU support



Closer Look

SFX-L is its own form factor away from SFF and regular ATX; the SFX part is self-explanatory, but the L stands for lengthened. What this essentially means is SFX-L is a small form factor power supply which has been slightly lengthened by around 30mm which allowed Silverstone to install a 120mm fan in as opposed to a lesser performing 80mm one. The SX500-LG does come with an SFX-ATX back plate adapter, which is great if you wanted to use this power supply in multiple builds etc.; the 80PLUS Gold rating is also a sign of quality usually and of course superior efficiency (when compared to Silver rated and lower of course).

Silverstone SX500-LG 2

Silverstone SX500-LG 3

Silverstone SX500-LG 5

The Silverstone SX500-LG is fully modular with a nice little twist, all the modular cables are flat which allows for epic cable management, especially in tight spaces or inside small form factor cases. In addition to this, the cable mounting plate has a clear and concise diagram of which cable goes where, including colour coded PSU connectors; only black and blue, but enough to make sure you don’t go trying to plug stuff in the wrong place!

Silverstone SX500-LG 4

Silverstone SX500-LG 6


Since we don’t currently have access to an ATE load tester, a multi-meter is used to show each of the power supplies performance on the 3.3v, 5v and 12v rails. Although we can’t do full load tests, we can provide relative information regarding variance and fluctuation of current and ripple on the rails which is integral and indicative of quality in a power supply.

To perform the above tests, the methodology will be as follows:

Test Setup:

Intel Core I7 4770k @ 4.5GHz
MSI Z97 Gaming 9 AC
1 x NVIDIA GTX 980
8GB (2x4GB) GSKill TridenX 2666MHz
2 x Crucial MX200 250GB
Silverstone SX500-LG SFX-L 500w

Voltages will be monitored via a multi-meter and the AC power draw will be monitored via a power monitor when drawn from the wall. For the idle test, the system will be simply booted up and let to run into windows and after 5 minutes when the power draw has levelled out, the readings will be taken.

To load and apply power to the power supply, a combination of IBT and Furmark will be run to put as much strain on the power supply as possible. After 10 minutes the readings will be taken and to ensure maximum strain, the CPU will be overclocked to 4.5GHz. Depending on the power of the power supply, multiple graphics cards could be used in line with how comfortable I feel the power supply will cope with such load.

ATX themselves specify that a fluctuation and variable of 5% is acceptable so to number crunch it means that:

3.3V = 3.135V-3.465V is acceptable

5V = 4.75V-5.25V is acceptable

12V = 11.4V – 12.6V is acceptable.

Any readings outside of these figures will be an automatic fail.

3.3V = 3.38v
5V = 5.08v
12V = 12.24v


3.3V = 3.27v
5V = 5.11v
12V = 12.28v


Final Thoughts

It’s clearly obvious to what type of consumer the Silverstone SX500-LG 500w power supply is aimed at; those who want exceptional quality in an SFF (small form factor) sized package. Is that actually the case though? Well, yes it is and those who have closely watched the SFF form factor gradually rise in popularity will surely note that Silverstone produce some of the best quality ones currently on the market. There is a lot of talk about other “brands” moving into the SFX power supply market and in that, comes competition, good competition though!

Silverstone even have a 700w model to cater for the most hard-core of systems which is easily enough to power an Intel Core i7 4770k and SLI GTX 970 system; just one example of how far SFX power supplies have come along in the last year or so. Not to deter from the 500w model, it has enough beef for virtually any single GPU configuration; one small enough to fit into a SFF sized rig that is!

With flat ribbon cables designed for fitting into tight spaces (oh matron), it makes sense to consider this particular unit for any kind of M-ITX system as only one graphics card can be used anyway; and then it is unlikely that it will come close to 500w peak either which as you can see from our test system, it handles what we threw at it during our “testing”. It falls well within regulated ratings and with its 80 PLUS Gold efficiency rating, it comes as little no surprise to us.

Would we buy the Silverstone SX500-LG 500w? Of course we would as not only is it a solid unit, it offers superb amounts of charisma in such a small package. For those wondering about value, I have seen these close to £100 and even then, it could be argued that £68 which is the current price it is to buy today, is nothing short of a bargain. That is my own opinion of course so please take that into consideration and regular ATX power supplies will offer better value overall, but not every power supply can fit into small form factor PCs. Consider the SX500-LG Play3r recommended!

Huge thanks to Silverstone for providing us with a unit.



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