SilverStone SX500-LG Power Supply Review

SilverStone's SX500-LG fits into the new SFX-L form factor. It's longer than normal SFX units, allowing for a larger fan that reduces output noise.

By Aris Mpitziopoulos
published

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Transient Response Tests

Advanced Transient Response Tests

For details on our transient response testing, please click here.

In these tests, we monitor the response of the PSU in two different scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V and 0.5A at 5VSB) is applied to the PSU for 200ms while the PSU is working at 20 percent load. In the second scenario, the PSU is hit by the same transient load while operating at 50 percent load. In both tests, we use our oscilloscope to measure the voltage drops caused by the transient load. The voltages should remain within the ATX specification's regulation limits.

These tests are crucial since they simulate the transient loads a PSU is likely to handle (such as booting a RAID array or an instant 100-percent load of CPU/GPUs). We call these tests "Advanced Transient Response Tests," and they are designed to be difficult to master, especially for a PSU with a capacity below 500W.   

Advanced Transient Response 20 Percent

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V12.229V12.056V1.41%Pass
5V5.109V4.935V3.41%Pass
3.3V3.350V3.231V3.55%Pass
5VSB5.082V5.018V1.26%Pass

Advanced Transient Response 50 Percent

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V12.169V11.957V1.74%Pass
5V5.087V4.923V3.22%Pass
3.3V3.315V3.161V4.65%Pass
5VSB5.034V4.987V0.93%Pass
Image 1 of 5

All rails registered larger-than-usual deviations, but in the end they all managed to pass the tests. The worst performer was the 5V rail, which went out of three percent.

Below are the oscilloscope screenshots we took during Advanced Transient Response Testing.

Transient Response At 20-Percent Load

Image 1 of 4

Transient Response At 50-Percent Load

Image 1 of 4

Turn-On Transient Tests

In the next set of tests, we measure the PSU's response in simpler transient load scenarios—during the PSU's power-on phase.

For the first measurement, we turn the PSU off, dial the maximum current the 5VSB can output, and then switch on the PSU. In the second test, we dial the maximum load the +12V rail can handle and start the PSU while it's in standby mode. In the last test, while the PSU is completely switched off (we cut off power or switch the PSU off by flipping the on/off switch), we dial the maximum load the +12V rail can handle before switching the PSU on from the loader and restoring power. The ATX specification states that recorded spikes on all rails should not exceed 10 percent of their nominal values (+10 percent for 12V is 13.2V and 5.5V for 5V).    

Image 1 of 3

We didn't notice any voltage overshoots or spikes during the turn-on tests, so everything went fine here.

Aris Mpitziopoulos
Aris Mpitziopoulos
Contributing Editor

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

9 Comments Comment from the forums
  • 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.
    Reply
  • 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?
    Reply
  • 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)
    Reply
  • 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.
    Reply
  • Aris_Mp
    Haven't noticed anything weird in my sample, else I would have mentioned it in the review.
    Reply
  • 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..
    Reply
  • 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.

    Reply
  • 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.
    Reply
  • 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.

    http://www.tomshardware.com/reviews/how-we-test-psu,4042.html
    Reply