Power SuppliesReviews

SilverStone’s SX700-PT – Mini Platinum Goodness

Platinum. That step above 80+ Gold that makes us question ROI (return on investment), saving the planet, and why we just can’t have +12V out of the wall. There’s a significant price premium for each 80+ ranking, however. But, in the world of SFF, efficiency is key – be it space or power. Wasted space is a sin in our little world, and wasted power leads to heat – the mortal enemy of SFF.

SilverStone showed us their SX700-PT at Computex this year – almost ready for production. Not only is this a true SFX power supply (not SFX-L), it is Platinum rated – great news on both fronts. The caveat though – the price. Retailing at US$186 at Amazon.com at time of writing, a full $16 more expensive than it’s SFX-L Platinum brother, and a hefty price increase over the competitors’ 600 and 650W products. However, Corsair has their Platinum SF750, available at NewEgg for US$193 – so the market segment the SilverStone PSU sits in isn’t as sparse as it may appear.

Regardless of the market, this is still an interesting product – let’s check it out.

The Specifications

+3.3V +5V +12V +5VSB -12V
Maximum Amps 22A 22A 58.4A 2.5A 0.3A
Range % ±3% ±3% ±3% ±5% ±10%
Regulation % ±1% ±1% ±1% ±1% ±1%
Ripple (mVp-p) 50mV 50mV 120mV 50mV 120mV


Model SST-SX700-PT
Max DC Output 700W
Power Density 882W per litre
Colour Black
Combined +3.3V and +5V 110W
Combined +12V 700W
Input Voltage 90V-264V
Input Frequency 47Hz-63Hz
PFC Active PFC(PF>0.9 at full load)
Efficiency 87% ~ 90% at 20% ~ 100% loading
MTBF 100,000 hrs
Operating Temp 0°C ~ 40°C
Protections Over current protection
Over power protection
Over voltage protection
Short circuit protection
Under voltage protection
Over temperature protection
Connectors 1 x 24 / 20-Pin motherboard connector (300mm)
1 x 8 / 4-Pin EPS / ATX 12V connector (400mm)
1 x 8 / 4-Pin EPS / ATX 12V connector (550mm)
2 x 8 / 6-Pin PCIE connector (400mm / 150mm)
2 x 8 / 6-Pin PCIE connector (550mm / 150mm)
6 x SATA connector (“300mm / 220mm / 100mm” x 2)
3 x 4-Pin Peripheral connector (300mm / 200mm / 200mm)
1 x 4-Pin Floppy connector (100mm)
Cooling System
Single 92mm FDB fan
Form Factor SFX
Noise Level 18 dBA minimum
Dimensions 125 mm (W) x 63.5 mm (H) x 100 mm (D)
Weight 0.96 Kg
Certification 80 PLUS Platinum
Compatible with ATX12V v2.4
Warranty 5 Years

The Unboxing

SilverStone has updated their packaging, a brighter blue instead of the black on previous units that we have reviewed.

What hasn’t changed is a clear outlay of the specs and features of the power supply on the box. Handy for those places that still have shelf displays, and for those who shop off the shelves at these brick-and-mortar retailers.

80+ Platinum, SFX (true SFX, not SFX-L), all Japanese capacitors (unlike the blend of Japanese and Chinese other brands use), a fluid dynamic bearing fan, fully modular and flat cables. Points I will come back to later in this review.

Opening the packaging, we see the manuals and warranty information.

Thorough as always, pinouts are provided for each connector.

What appears to be polyethylene closed cell foam (LD-PE) protects the SX700-PT. Sigh. Not easily recyclable in a domestic setting. Please, SilverStone, and all manufacturers, use cardboard or moulded pulp to protect your products. Even soft plastic bags are easier to recycle than this (literal) garbage.

The power supply itself is protected in a plastic bag.

And the cables are held within the cardboard shroud – and there are a lot of them!

The SX700-PT

In a true SFX form factor, with a 92mm fan, this is one of the most power-dense power supplies on the market today – w00t! 882W per litre.

The SX700-PT is based on what appears to be a newer platform, as the modular connector layout does not match any other products in SilverStone’s lineup. I will delve into this later in the teardown.

Specs! Also of note is the retail serial sticker – this isn’t a pre release press sample, it’s a retail unit, so what you see in this review can be considered truly representative of the product in the market.



The cables are in the typical SilverStone flat cable style as per other products in the lineup.

One change though, is that the extra sense connector uses thinner wires than previous products, aiding in cable management. Some users may hate the flat cables – not me. I’m a fan, as they can be molded into shapes and hidden better than the individually sleeved cables from other products. They can also be carefully separated into smaller bundles to aid in routing.

The Testing

So, how does one test a power supply of this calibre? A full load testing apparatus would cover all the bases, but costs in the tens of thousands. The alternative is load testing with an actual system – more representative of a real world use case. It’s not ideal as a sole performance metric, hence our comment at the beginning of the article regarding using our review as a source of knowledge to accent others in your search for a power supply.

To load test the power supply, I threw together a powerhouse SFF-esque system, namely;

Case Bench
CPU AMD Ryzen 5 1600X
Motherboard ASRock B450M Pro 4
Graphics Card 2x Sapphire RX580 Nitro+ 4GB
RAM 2x 8GB G-Skill Flare-X 3200MHz
Storage 320GB HDD
Cooling system Custom watercooling loop (Barrow blocks, EKWB res, EKWB DDC 3.1 with top, Aquacomputer Modularity 240 radiator

All in all, PSUcalc puts this system in at 650 watts, a solid test that should be well above the wattage levels of most SFF systems.

As an aside, I’m powering this system from the (better) 230V we have in NZ, which means I gain an average 2% boost in efficiency over those on the (weaksauce) 110V systems.

Loading up the system with Prime95 Blend on all 12 threads, plus Furmark, full load is achieved. Radiator fans hit full speed, and the pump ramps up to compensate for the massive heat load.

The SX700-PT takes this load like a trooper. The fan does ramp up, of course, but it still remains quiet, with a great smooth aural character. One thing that is important to note – this power supply does not have a fanless mode. Between 0-420 watts, the fan is rated to spin at just under 1500RPM. Ramping up the load past here nets a smooth curve up to a peak of 3000 RPM.

I loaded the system like this, in an ambient of 28c (yeah, my office ventilation is horrible), for a few hours. No stress, no strain, and the system remained stable while still process prime numbers and the fuzzy donut of doom. The power supply, whilst having the fan ramped up to near full speed, stayed warm, not hot – very impressive.

At 650W load, the SX700-PT would be drawing around 722 watts , or 730W in 110V markets.  (I really need to buy a Kill-a-Watt or similar!) This netts a heat output, or inefficiency of 72W. In comparison, SilverStone’s SX700-G, a gold rated 700W SFX power supply, would be drawing around 730W (747W/110V), meaning an 80W waste on 230V, and 97W waste on 110V.


Now for the savings – and the “Return on Investment” I mentioned at the beginning. At around US$0.15 per kWH, running this test system on a Platinum power supply, at full load, for a year, in this case would save you US$10.50 (or $52.50 over the 5 year warranty period), versus a Gold rated unit. That’s on 230V. On 110V, the savings would account to around US$22 a year. Now, let’s be honest – outside of servers and mining, nobody really runs their system at full load all day, every day. This does negate the savings significantly.

The environmental benefit is a trade-off though. Yes, we save power, but at the cost of producing a new power supply (assuming you are buying for an existing system). To be honest, it’s a difficult choice – is the added cost worth it for the power (and thus emissions/environmental benefits), versus how you use your system.

This is, however, an argument as old as electricity itself. It’s your decision in the end, really. My argument would be – if you need to upgrade to a higher wattage power supply, or replace a dead unit, go Platinum. If you’re considering replacing your power supply on a like-for-like basis just to get the better rating, it’s not worth it.

The Teardown

The fan within the SX700-PT is a Globe Fan S0921512HB, a two pin, 92x10mm FDB fan, which appears to be made specifically for SilverStone. This has been the stalwart of SilverStone SFX PSU cooling for some time, and is an average, albeit not PWM controlled, fan. More info on the fan can be found in our article on the SX800-LTI, here.

Inside the SX700-PT. The platform appears to be a revision of the one found in the SX650-G (and SX500-G) – seen here, implying the use of a Sirfa platform for this power supply. Newer components and tweaking gained efficiencies, leading to the Platinum rating on this power supply. (Although, the SX650-G wasn’t too far off Platinum to begin with!)

The modular cables PCB is completely different from the SX650-G linked above – one of the revisions made to this platform. One reason for this is a big jump in the quantity of outputs – adding a third peripheral connector (for SATA or Molex), and a second EPS connector – Threadripper boards rejoice!

Rubycon caps appear to be the order of the day in this power supply. Nice!


The soldering is generally good, excepting the hand added mods. There seems to be an excess of solder here, with close gaps between the solder and other component leads. Although time will tell as to the longevity of the “bodge” wires added to the top right to added current capacity – they just don’t fill me with confidence!

A thermal pad helps transfer some heat through the plastic insulation sheet to the shell of the PSU. Remember to put this plastic shield back if you disassemble your SF700-PT – it insulates the board from the case and there are some very tight tolerances.

The Conclusion

It’s a performer, that’s for sure. It also comes at a price – especially noticeable with the release of Fractal Design’s 650W SFX-L unit recently, which comes in at US$109.99 (when in stock – it appears to be out of stock at both Amazon and NewEgg at time of writing). You lose 50 watts and a couple of percentage points of efficiency, but you’re also paying only 60% of the price. It’s up to you where the value proposition lies – higher quality, 50 watts more, true SFX size, or the other offerings on the market. One thing’s for sure though, you do pay a premium to live at the bleeding edge.

Also of note is the warranty period – with SilverStone providing 5 years of warranty on the SX700-PT. This is half the warranty on the Fractal Design and Seasonic units, less than the 7 years on Corsair and FSP units, which is significant. Whilst a longer warranty doesn’t necessarily denote a better quality product, it is a little tight on such an expensive power supply. Only time will tell as to the longevity of any new product.

Overall, a solid construction. Dense power componentry from high quality brands. Whilst we can’t analyse the minutiae of the PSU’s performance as mentioned above, we can take cues from design and component choices. From experience with other power supplies, this unit is of a high quality.

Is the SX700-PT a good product? Yes. Is it good value? Objectively, no. I can’t recommend the SX700-PT at the current price point, even with the performance and efficiency. I love bleeding edge tech and high spec numbers, but if your budget isn’t unlimited, and you don’t need the outright specs the product offers (true SFX, 700w), it’s hard to justify.


  • Platinum
  • True SFX form factor
  • 700W!
  • Small power switch is nice for cases with constrictive PSU mounting


  • Price
  • The foam packaging
  • No fanless mode
  • No included ATX to SFX mounting bracket.


  • Soldering seems to be sub standard for SilverStone in some places

This review sample was provided by SilverStone.

Here at SmallFormFactor.net we give manufacturers the ability to be part of the community. We offer a right to reply to our hardware reviews. If a manufacturer responds with any feedback or corrections, their comments will be posted here.

Platinum. That step above 80+ Gold that makes us question ROI (return on investment), saving the planet, and why we just can’t have +12V out of the wall. There’s a significant price premium for each 80+ ranking, however. But, in the world of SFF, efficiency is key – be it space or power. Wasted space is a sin in our little world, and wasted power leads to heat – the mortal enemy of SFF.
SilverStone showed us their SX700-PT at Computex this year – almost ready for production. Not only is this a true SFX power supply (not SFX-L), it is Platinum rated – great news on both fronts. The caveat though – the price. Retailing at US$186 at Amazon.com at time of writing, a full $16 more expensive than it’s...

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sff is life
May 8, 2018
Nice and thorough breakdown! You should gift yourself a kill-a-watt this holiday season ;)

Good to see more competition in the space even if it is not a clear winner.

With high wattage SFX commonplace they are starting to become routine (which is a good thing, imo mainstream builder can start defaulting to SFX for a few bucks more). My fantasy is we see even more innovation in sub 450w range (HDPLEX had a good 2019, hopefully we see more in 2020)
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John Morrison. Founder and Team Leader of SFF.N
Original poster
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
A Kill-a-watt is in the to-buy list for January :) Gotta pay bills, buy xmas presents, pay more bills, survive the holiday season pay cycle and then on to new beginnings.

It felt weird enough decommissioning my dual GPU desktop into a glorified test rig XD
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