SilverStone SX1000 Platinum

The SilverStone SX1000 is the strongest small factor unit we have tested so far, and it has enough connectors to support a strong gaming system. This is why it is out top choice in the best power supply for gaming guide for this category. 

The best part is that with lower than 700W loads, its noise output won’t bother you, unless you are super-sensitive, in which case you should not invest on in a high power density power supply in the first place. 

Since everything small and powerful is usually expensive, especially in the IT world, the SX1000 will empty your wallet. That said, PSUs are inexpensive given the vital role that they have in every system. Not long ago people paid over 1000 dollars to acquire a mid-level graphics card, so a 250-300 dollar power supply doesn’t look that expensive, especially if you consider that you will keep it for many years.

Specifications

SilverStone’s SX PSU line consists of two SFX-L units with 750W and 1000W capacities. The SX1000 has a 969W-per-liter power density, among the highest we have seen so far. 

SilverStone equipped it with two EPS and six PCIe connectors to ensure it can deliver its full power without any problems. Moreover, all cables are modular, making the PSU’s installation a breeze. Because of the small PCB, the temperatures at the internals can go high, so a double ball-bearing fan was used, which can handle hot conditions without any problems. In general, DBB fans are considered of higher quality compared to FDB, but they are more expensive and this is why the latter dominate the high-end market.

The platform's design is clean, despite the high power density. Enhance Electronics, the OEM, used large heat sinks on the primary side, with perforations on the APFC heat sink to allow airflow to the components installed below it. There was no room on the small PCB for a single large main transformer, so Enhance used two smaller ones, installed in parallel. The filtering caps on both primary and secondary sides are of high quality, and the same applies to the Globe Fan DBB fan, which measures 120mm across. 

One of the notable advantages of the SFX-L form factor is that it allows up to 120mm fans, keeping noise output low, while the SFX units are restricted to 92mm fans in the best-case scenario.

The 12V rail can deliver the PSU’s full power, and the minor rails can go up to 125W combined.

With two EPS and six PCIe connectors, the PSU doesn’t have a problem delivering its full power. There is no 12+4 PCIe connector, but hopefully SilverStone will soon update this platform. The cables are short, because this PSU is meant for small chassis, but SilverStone should probably offer a version with longer cables, including an SFX-to-ATX adapter.

Performance

Load regulation is tight enough at 12V but not so tight on the minor rails. Ripple suppression could also be better at 12V. More filtering caps are needed for lower ripple on this rail, but the PCB is not large enough to accommodate them. In-cable caps could offer a performance boost here. With better ripple suppression at 12V, the SX1000 could easily achieve top marks versus all manner of PSU.

The hold-up time exceeds 17ms, which is not as easy in high-power density PSUs because there is restricted space to install large enough bulk caps. Though the inrush currents are at normal levels.

Efficiency is high with normal loads and super-light ones, but it could be higher with light loads. The 5VSB rail also achieves top efficiency scores. Vampire power is low with 115V, but we would like to see below 0.1W with 230V input.

The transient response at 12V is among the best we have ever seen in this form factor category, meeting many normal dimensions PSUs with similar capacity eye-to-eye. The other rails also have good transient response.

It is amazing to see an SFX-L PSU delivering close to 1500W. That said, it would be safer if the +12V OCP and the OPP triggering points were set more conservatively, at around 130%. Lastly, there is over temperature protection, and the other protections operate fine, according to our results.

The average noise output is higher than 35 dBA because of the increased fan noise under high loads. It would be extra tough if not impossible for such a high power density PSU to remain quiet under high loads.

Final thoughts

The SX1000 is the strongest small form factor PSU available on the market today, and in reality, it is way stronger than its paper specs since we pushed it close to 1500W. The main alternative to this PSU is the Corsair SF750, but we'd still opt for the SilverStone in a pinch.

Enhance, the OEM behind this platform delivered a solid unit to SilverStone, with good build quality and top-notch parts. The only downside is that because of the small PCB, not many filtering caps could be installed so ripple at 12V is not that great. Silverstone should probably use in-cable caps to enhance ripple suppression. This type of cables is not preferred by the majority of users, because it makes the installation tougher, but this is a small price to pay if you ask us, for lower ripple, which plays a crucial role in the system’s reliability and longevity.