Conclusion
The SilverStone ST1200-PTS is the largest capacity power supply we have seen here at TheFPSReview. However, it is by no means the first 1200W unit on the market or the first 1200W unit from SilverStone on the market. Like the ST1000-PTS, however, it is the smallest ATX12v form factor unit from SilverStone we have seen and, probably, the smallest currently marketed in this capacity range in general. This means that, once more today, we have the opposing design goals of producing both a large capacity unit and a very small package. These competing interests could certainly cause problems especially as this unit is 200W larger in capacity than the previous ST1000-PTS. However, SilverStone is not exactly new to this sort of thing. So, the question then becomes; will that pedigree shine through today or not? Let’s see.
Build Quality
Today’s SilverStone ST1200-PTS starts things off with a build quality that is excellent just like its smaller capacity brother the ST1000-PTS. Externally, the finish that this unit has is very much like what we typically find these days being black and slightly textured. We also see that the unit is equipped with flat FlexForce style cables. When we move to the interior of the unit, we see the same platform that is used in the ST1000-PTS. Thus, the topology is very modern and the component selection is generally very high quality. These components include Nippon Chemi-con and Suncon standard capacitors coupled with Unicon and CapXon solid capacitors while the fan is a modified sleeve bearing (HYB) type. The actual integration is very good, though cramped, and the soldering is excellent. Moving on to the support side of things, we know that this unit is covered by a 5-year warranty and very good documentation.
Load Testing
Today’s SilverStone ST1200-PTS provides us with passing, and even good, results overall. Indeed, we saw voltage regulation of up to 0.24v on the 12v rail, 0.09v on the 5v rail, and 0.1v on the 3.3v rail. This voltage regulation is certainly very good in absolute terms and is well within the ATX12v specification limits as well as what SilverStone advertises for the unit. However, among “normal” sized ATX12v power supplies this unit is not going to be the absolute best among high end or flagship type products. Given the size of this unit, however, there is some amount of leeway that should be given here.
Moving on to the unit’s efficiency, we see that it ranged from 90.65% to 92.89% at 120v and of 89.41% to 91.89% at 100v. When we look at the 80 Plus tests, we see that the ST1200-PTS posted efficiency values of 92.81%-93.31%-91.08% using 80 Plus’s load testing parameters. This put the unit right in the 80 Plus Platinum standards. Lastly, this unit passed our Torture Test in fine shape which is good to see from this unit given the extra constraints placed on it.
When we look at the Transient Load Tests results for the SilverStone ST1200-PTS today, we see results that are good and look a lot like what we saw above. When directly loaded, the 12v rail showed a peak change of ~300mV and the 5v rail had a peak change of ~90mV. During the 12v load, the unloaded 5v rail saw a peak change of ~60mV. In absolute terms, these results are passing. In relative terms, we have not seen any other 1200W units here at TheFPSReview yet. However, among others on the market, this unit is going to be rather competitive in this regard which is great for a small unit like this.
DC Output Quality
The DC Output Quality results for the SilverStone ST1200-PTS were passing. Today, we saw peak values of ~65mV of ripple/noise on the 12v rail, ~30mV on the 5v rail, and ~30mV on the 3.3v rail. When it comes to absolute values, these values are well within specification limits, but the minor rails are pushing over ½ of that limit. When it comes to relative values, there are other 1200W units on the market in the flagship realm which will do much better than this. However, none of them are this small as this unit is and, so, none of them are dealing with the issues that causes.
Noise
Today’s SilverStone ST1200-PTS, like the ST1000-PTS before it, is a small ATX12v unit which means space for a large fan will be limited. On top of that, this unit cranks up the difficulty level today by going from 1000W to 1200W in the same small space. These two factors make noise output potentially problematic. On the flip side, this unit does the same very high efficiency and fan type that we saw in the ST1000-PTS which did well enough in this aspect of testing. So, then, what was the noise like for the ST1200-PTS?
In our testing, this unit was very well behaved much like its smaller sibling. It was, again, not until the Torture Test and the full load tests that we could discern the fan adding noise to our load testing environment. Given the circumstances that we used to reach that noise output, this unit seems to be very nicely behaved like the ST1000-PTS was and should work out well for most users who need such a large power supply in such a small package.
Final Points
Like the ST1000-PTS, the SilverStone ST1200-PTS is an interesting unit today as SilverStone is once more showing up with a pint-sized ATX12v power supply packed with power. In doing so, the ST1200-PTS gave us excellent build quality, good voltage regulation, and good Transient Load results while also being relatively quiet. The one big area that this unit suffered was the DC Output Quality. However, at no time was this unit out of specification in this aspect, or any other that we tested today. Thus, this unit is easily passing and represents a power supply that is above average overall.
As always then, that leaves us with the question of price. Availability is fairly limited on these units still and that means the pricing is still a bit skewed because of this. Amazon, though, lists it at $261.06. That price is not bad in the grand scheme of things and is competitive with other 1200W options. That makes this unit very interesting in that it is trading certain features (size) for a bit of performance fairly evenly and without a huge price premium. Since it is a tradeoff, though, this means that this unit is not going to be for everyone. If absolute performance is what you want, then it is not for you. If size is what you are after without truly sacrificing much in the performance category, then this unit is for you. Either way, the pricing is better relative to the competition than what we saw from the smaller ST1000-PTS. So, no matter why you buy this unit, you are going to be at least getting a fair deal at today’s pricing.
