The ST1200-PT would achieve a much higher overall performance rating score if its ripple suppression on the minor rails was within spec, under high ambient. Moreover, we would like to see an accurate power ok signal and the fan profile should be less aggressive. On the other hand the build quality is good, load regulation is satisfactory and the PSU is equipped with a great number of cables. The magnetic fan filter is a nice addition as well and with 18cm depth, the PSU will fit into most ATX cases. The competition in this price range is tough though, and offers even longer warranty periods.
Full power at 46°C
Ripple suppression at +12V
Satisfactory load regulation
8x PCIe & 2x EPS connectors
Paintjob & Finish
Ripple suppression on the minor rails at high ambient
Not accurate Power Ok signal
3.3V rail performance in Advanced Transient Response tests
Noisy under tough conditions
Why you can trust Tom's Hardware
SilverStone ST1200-PT Power Supply Review
According to SilverStone its Strider Platinum line satisfies the requirements of professionals and enthusiasts. The family includes six members with capacities ranging from 550W to 1.2kW. Only the two top models are equipped with a 139mm Air Penetrator fan and FF141 magnetized fan filter. The other Strider Platinum units come with 120mm fans. They're smaller, so a 140mm fan wouldn't fit.
The ST1200-PT we're looking at today should have what it takes to drive a very potent system. In addition to high capacity, the PSU also includes two EPS and eight PCIe connectors to feed multiple graphics cards and a high-end motherboard.
For most enthusiasts, a 1200W power supply is overkill. But there are still folks building boxes with CrossFire and SLI configurations, plus aggressively overclocked CPUs. As we've mentioned before, these components may sip power conservatively in stock form, but higher frequencies and voltages have a big effect on consumption.
Moreover, many PSUs achieve the best efficiency under loads that fall within 40-50% of their maximum-rated capacity. You could argue that gaming systems won't always operate under full load, keeping them out of this sweet spot more often than not. But Platinum- and Titanium-class units are usually highly efficient under light loads as well. Even if your system sips power at idle, you won't suffer big energy losses with these high-capacity models.
We generally advise that you calculate your system's power needs under full load, and then buy a PSU with at least 20% more capacity. Further, favor more efficient units when your budget allows. Doing so allows you to save money on electricity and decrease your carbon footprint, since less energy goes wasted.
The ST1200-PT is 80 PLUS Platinum-rated. Unfortunately, its maximum operating temperature for full-power delivery is rated at 40°C, which is typical of even high-end Enhance Electronics platforms. The available protection features include everything except OCP on the +12V rail (which is meaningless anyway in such a high-capacity PSU with one +12V rail). Given the low temperature rating, it is nice to see over-temperature protection. Enhance is one of the few OEMs that offers OTP in most of its designs.
Measuring 18cm deep, the ST1200-PT is pretty small for a 1.2kW power supply. SilverStone takes downsizing seriously; it recently announced an SFX-L-based unit with 800W max power!
SilverStone's five-year warranty is long enough, though it's worth mentioning that competing offerings are covered by warranties as long as 10 years.
|Total Max. Power (W)
|1200 (1250 Peak)
The single +12V rail is powerful, offering up to 100A output. The minor rails are quite strong as well, with 120W maximum combined power.
The only downside is the 5VSB rail, which is weak at up to 12.5W. Given the PSU's capacity, the 5VSB rail should have at least 3A max current output, with 4A being ideal.
Cables And Connectors
|Connector Count (Total)
|ATX connector 20+4 pin (550mm)
|4+4 pin EPS12V (760mm)
|4+4 pin EPS12V (560mm)
|6+2 pin PCIe (560mm)
|Four-pin Molex (610mm+150mm+150mm) / FDD (+150mm)
|6 / 2
The main ATX cable could be a little longer, reaching 60cm, since a 1.2kW PSU is probably destined for a full-tower chassis. SilverStone equips this PSU with two EPS cables, one of which is 20cm shorter than the other. The number of PCIe cables is adequate, and one of the ST1200-PT unit's advantages is that each PCIe cable only hosts a single connector. This might cause some trouble during the installation and cable management process, but it should also facilitate tighter load regulation.
The number of SATA and four-pin Molex connectors is pretty large, and the distance between connectors is ample at 15cm. Finally, the main ATX, EPS, and PCIe cables use 16-gauge wires for lower voltage drops under higher loads.
Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.
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Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.
Wow!! Extremely impressed with Aris's more thorough "Advanced Transient Tests" !!Reply
Great to see a reviewer who never stops evolving his work!!
Amazing work Aris !!!
Nice review, Aris. $233 is a lot to spend on a PSU. You can get a Corsair HX1200i for $210 after mail in rebate, which is a well-regarded PSU with a 7-year warranty.Reply
"...and as you can see, the glossy silver surface makes taking pictures difficult."Reply
It sure does, because the pictures have the exterior looking like matte black.