SilverStone SX500-LG Power Supply Review

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Efficiency, Temperatures And Noise


Our efficiency testing procedure is detailed here.

Using the results from the previous page, we plotted a chart showing the efficiency of the SX500-LG at low loads and at loads equal to 10 to 110 percent of the PSU's maximum rated capacity.

If we take into account its compact form factor, which imposes some limitations, the SX500-LG fared well against its ATX competition. Compared to its SFX siblings, it was behind the SX600-G at normal loads. At light loads, however, it managed to take the lead. Although the difference in efficiency at normal loads with 230V input was significant, with 115V, the SX500-LG was slightly ahead (0.6 percent).

Efficiency At Low Loads

In the next tests, we measured the efficiency of the SX500-LG at loads significantly lower than 10 percent of the device's maximum capacity (the lowest load the 80 PLUS standard measures). The loads we dialed were 20, 40, 60 and 80W. This is important to represent when a PC is idle with power-saving features turned on.

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Test12V (A/V)5V (A/V)3.3V (A/V)5VSB (A/V)Power DC/AC (W)Efficiency (%)Fan Speed (RPM)Fan NoisedB(A)PF/AC (V)

At low loads, efficiency was high, with three out of the four tests passing the 80 percent mark. In addition, the PSU was almost inaudible; it stayed below 30 dB even during the last test, which was conducted at an ambient temperature of close to 40 degrees C (104 degrees F).

5VSB Efficiency

The ATX specifications state that 5VSB standby supply efficiency should be as high as possible, recommending 50 percent or higher for a load of 100mA, 60 percent or higher for a load of 250mA and 70 percent or higher for a load of 1A or more.

We take four measurements: one each at 100mA, 250mA and 1000mA, along with the full load the 5VSB rail can handle.

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Test5VSB (A/V)Power DC/AC (W)Efficiency (%)PF/AC (V)

Although 115V efficiency on the 5VSB rail was pretty good, we cannot say the same for 230V. Nonetheless, the SX500-LG performed much better than the SX600-G, which has even smaller dimensions and thus is subject to more limitations.

Power Consumption In Idle And Standby

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Mode12V5V3.3V5VSBPower (AC)PF/AC Volts

In the table above, you can see the power consumption and voltage values of all of the rails (except 12V) when the PSU is idle (powered on, but without any load on its rails), and the power consumption when the PSU is in standby mode (without any load at 5VSB).

In standby mode, the PSU consumes only 0.11W, and with 230V, the power consumption increases to 0.25W. That's still half of the maximum consumption set by the ErP Lot 6 2013.

Fan RPM, Delta Temperature And Output Noise

Our mixed noise testing is described in detail here.

The following chart illustrates the cooling fan's speed (RPMs), and the delta between input and output temperature. The results were obtained at an ambient temperature between 37 and 45 degrees C (99 to 113 degrees F).

The next chart shows the cooling fan's speed (RPMs) and output noise. We measured acoustics from one meter away, inside a small, custom-made anechoic chamber with internals completely covered in soundproofing material (be quiet! Noise Absorber kit). Background noise inside the anechoic chamber was below 18 dB(A) during testing, and the results were obtained with the PSU operating at an ambient temperature of 37 to 45 degrees C.

The following graph illustrates the fan's output noise over the PSU's entire operating range. The same conditions of the above graph apply to our measurements, but the ambient temperature was between 28 and 30 degrees C (82 to 86 degrees F).

At loads of up to about 250W, the PSU is dead silent, whereas with typical loads, it is about 28 to 31 dB. Therefore, its output noise most likely will be covered up by the noise of the rest of the system components. In a worst-case scenario under full load, the noise reaches about 40 dB, which is still low enough for a compact PSU with 500W of capacity.

Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

  • Giannis Karagiannis
    Nice review! Indeed, the price is high but this is common with non standard ATX size PSUs. Apart from the high price it looks like a very good unit however.
  • PaulBags
    I'm waiting to see the 700w platinum version of this in review. If we can get a 700w platinum sfx-l, how long until we can get shorter and/or higher wattage fanless atx?
  • Aris_Mp
    I will ask for their 700 W model as well.

    As for higher wattage fanless ATX units, only with Titanium efficiency (for less energy dissipation)
  • jtd871
    YMMV, but there are people who have reported a galloping or chirping noise associated with this model. It's not clear if it's the fan, the thermistor that turns the fan on and off or a combination of both. Based on the ambient testing temps for this review, it might not have been noticed or noticeable. Discussion on for those wanting more info.
  • Aris_Mp
    Haven't noticed anything weird in my sample, else I would have mentioned it in the review.
  • Vlad Rose
    Still not compatible with their first generation Raven RVZ01 models. Be careful if you buy one through an online retailer as you might get back stock as Silverstone never bothered to call it a revision change..
  • mikelim2000
    Got the same PSU, no weird sound, almost dead silent. My PC is dead silent, no case fans, only other fan is the Be Quiet! Shadow Rock LP for my cpu and that's literally dead silent.

  • ThePSU
    Honestly....Aris no mean to offend you but you barely explain how you test these, what equipment you use, or anything. Just a bunch of oscillating graphs is not making you a confident reviewer to me. One must reveal how they come up with these numbers in detail and equipment used. Otherwise until I can myself replicate these things, your reviews are utterly useless to me.
  • Aris_Mp
    I am not easily offended no worries. There is a whole article about this. And also there are links to this article right before each new test, in all of my reviews. For me as well a reviewer that doesn't share is methodology and equipment isn't a trust worthy one.,4042.html