Welcome to this special double feature PSU review! On the docket today are the SilverStone ST30SF V2.0 and the ST45SF V3.0, which are non-modular, Bronze-rated units with 92mm cooling fans of 300W and 450W capacity respectively. As the revision number at the end signifies, these are updated versions of previous SilverStone SFX power supplies and as such, they retain the old naming scheme.
After reviewing high-end SFX-L monsters like the SilverStone SX700-LPT, Lian Li PE-750, and SilverStone SX800-LTI, it feels a bit strange to be reviewing more down to earth units like these, but realistically 300-450W would cover the vast majority of SFF builds. So let’s take a look!
Table of Contents
A disclaimer first before we get started: SFF Network does not currently possess the expertise or equipment to fully test the electrical performance of PC power supplies, and as such, this article should not serve as the sole data point in determining whether to purchase this product. We’ll be able to contextualize the utility and experience of using this unit with others in the market place, but we’d suggest having our own review supplement those by others who have the hardware and capability to do more thorough analysis of electrical performance, especially at higher wattages.
Also, since both units basically look identical from the outside, all of the following pictures are of the ST30SF V2.0 unless otherwise noted.
The Box
I’m glad to see that SilverStone is not shying away from showing that these units are non-modular, starting right at the picture on the front of the box. All too often, staged product shots of mice, keyboards, and PSUs are a bit dishonest, and try to obscure whether the product is actually wired or not.
Also on the front is some marketing material, mostly going over the basic specs of these units:
- ATX PSU mount support via a bundled adaptor bracket
- 300W/450W continuous power rating at a 40°C operating temperature
- 80 PLUS Bronze rating for the power efficiency (82% / 85% / 82% efficiency at 20% / 50% / 100% load)
- Single 12V rail
- 92mm cooling fan with a 18dBA minimum
- And this unit features Active PFC
Coming around to the back of the box is the same marketing in several difference languages, as well as a graph demonstrating the Bronze-rating efficiency curve and the fan speed curve.
On top are a few more specs, the load table, and connector list. As we like to see for a modern PSU, the 12V rail is capable of outputting the full rated wattage alone.
The inside of the box is a simple affair, as reflected by the price point.
Accessories
Accessories for both units consist of the unit-specific manual, general SilverStone PSU manual, power cord, ATX adapter bracket, and two sets of screws. The small flat head (countersunk) screws are for attaching the SFX power supply to the ATX bracket, while the other screws are for mounting either the SFX unit directly to the case or the bracket to the case.
These units ship with ATX adapter brackets, but Tony from SilverStone told us at CES that future SFX and SFX-L units from the company will not, in order to reduce the cost for those customers using the products as intended (in a SFX-only case). I suspect the 300W and 450W here still included them because they are revisions of older units which also bundled them.
Cables
Cable lengths for the 300W are as follows from top to bottom:
- 1x 6-pin PCIe (400mm)
- 24-pin (20+4) motherboard (300mm)
- 1x 4+4-pin CPU (400mm)
- 3x SATA (300mm / 200mm / 100mm)
- 2x 4-pin Molex + 1x Floppy (300mm / 200mm / 200mm)
I would rather see another SATA connector on the end of the Molex strand for connecting an out of the way ODD or HDD and have the floppy connector broken off into an adapter. Other than that though, I’m fine with the connector selection and the cable lengths are appropriate for what these units are intended for.
The 450W has an almost identical set of cables and connectors, the only difference being the addition of a 6+2-pin PCIe connector so a more demanding video card can be hooked up to take advantage of the extra wattage. The cable length to the 6+2-pin is 400mm and the 6-pin is 150mm past that.
The Power Supply
For what are SilverStone’s budget SFX units, they are still pretty sharp looking in my opinion, and the centered fan that takes up most of the top side is much nicer looking than the offset 80mm fan of the previous revisions.
The ST30SF V2.0 (including the cables) weighs 1.02kg and the ST45SF V3.0 comes in at 1.09kg.
And here is the typical label with the load table, warning, and various certifications. One notable difference between these new units and their predecessors is a slight reduction in the rated amperage for the 5V and 3.3V rails.
Specifically for the ST30SF, the V1.0 can do 20A on the 5V while the V2.0 can only do 16A, a 20W reduction. This could pose a problem for 5V heavy builds, like a fully loaded NAS, but SilverStone will apparently continue to sell the ST30SF V1.0 for at least a few years to cater to those customers.
On the other side, the unit is clearly identified as being of the 2.0 revision (and the 450W likewise features a V3.0 sticker), along with the serial number and QC check stickers.
The rear of the units ares extensively vented, which I like to see. These are much lower wattage power supplies than the other PSUs I’ve reviewed so far, but they are also of lower efficiency, so they need all the help they can get in the airflow department to keep temps (and thus noise) down.
There is a plastic shield on the inside and the corners of the PCB are inset, but not by very much, so take care if using nonstandard screws.
Non-modular ATX power supplies are typically monstrosities of tangled wires, but since the cables on these are fewer in number and shorter in length, it actually doesn’t look too bad.
As I mentioned, since these units are only Bronze-rated, anything to improve cooling is a plus. So while I like the fan size increased from 80mm to 92mm, the lack of a wire grill is disappointing, but to be expected considering the price point SilverStone is targeting.
Testing
As mentioned at the beginning of the review, we currently lack the expertise and equipment to properly evaluate the electrical performance of power supplies to a complete extent, so the following data is more to demonstrate that the Silverstone ST30SF V2.0 and ST45SF V3.0 are capable of powering the test system with no issues.
A quick note:
To account for the lower wattage of these units compared to previously reviewed PSUs, a single GTX 1060 was used for Tests 1-4 on both units, then the GTX 1060 was swapped for a Radeon R9 280X for Test 5 on the 450W.
Test hardware:
| CPU | Intel Core i7-5930K |
| Motherboard | Asus X99-M WS |
| Cooling | Noctua NH-C14S with black NF-A14 PWM |
| PSU | SilverStone ST30SF V2.0 and ST3045SF V3.0 |
| RAM | Crucial Ballistix Sport 16GB (2x8GB) DDR4 2400 |
| Video Card | 1x EVGA GTX 1060 SC / 1x MSI Radeon R9 280X Gaming |
| Storage | Samsung 840 EVO 500GB |
| Case | Lian Li PC-6X tray |
| OS | Windows 10 64-bit |
Test equipment:
- Brand Electronics 4-1850 power meter, used to measure the AC draw of the system.
- Reed AT-6 non-contact tachometer, used to measure the fan RPM.
- Pax Instruments T400 temperature datalogger with Omega thermocouples, used to measure ambient, intake, and exhaust temps.
- Fluke 83 III multimeter to measure voltage.
Methodology:
Each test is run for 10 minutes, and then readings are taken before moving on to the next test. As mentioned earlier, the GTX 1060 was used for Tests 1-4 on both power supplies under test. Then for Test 5 on the ST45SF V3.0, the EVGA GTX 1060 was swapped for a single MSI R9 280X.
ST30SF V2.0 Test Results:
| Wattage (AC) | Ambient Temp | Intake Temp | Intake Delta | Exhaust Temp | Exhaust Delta | Fan RPM | 12V | Test |
| 45W | 23.7°C | 24.8°C | 1.1°C | 30.6°C | 6.9°C | 765 RPM | 12.17V | Idle |
| 115W | 23.6°C | 25.4°C | 1.8°C | 34.4°C | 10.8°C | 780 RPM | 12.16V | 2 threads Prime95 Blend |
| 165W | 24.2°C | 27.0°C | 2.8°C | 39.8°C | 15.6°C | 840 RPM | 12.16V | 10 threads Prime95 Blend |
| 304W | 25.6°C | 31.5°C | 5.9°C | 41.0°C | 15.4°C | 1780 RPM | 12.15V | 10 threads P95 Blend, FurMark 1x 1060 720p no AA |
The SilverStone ST30SF V2.0 powered my test setup with no issues.
ST45SF V3.0 Test Results:
| Wattage (AC) | Ambient Temp | Intake Temp | Intake Delta | Exhaust Temp | Exhaust Delta | Fan RPM | 12V | Test |
| 43W | 23.7°C | 24.0°C | 0.3°C | 27.1°C | 3.4°C | 1020 RPM | 12.13V | Idle |
| 110W | 23.6°C | 24.6°C | 1.0°C | 30.0°C | 6.4°C | 1040 RPM | 12.12V | 2 threads Prime95 Blend |
| 160W | 24.0°C | 24.6°C | 0.6°C | 32.2°C | 8.2°C | 1060 RPM | 12.12V | 10 threads Prime95 Blend |
| 290W | 24.9°C | 30.0°C | 5.1°C | 36.9°C | 12.0°C | 1530 RPM | 12.10V | 10 threads P95 Blend, FurMark 1x 1060 720p no AA |
| 415W | 23.9°C | 34.7°C | 10.8°C | 47.5°C | 23.6°C | 2450 RPM | 12.09V | 10 threads P95 Blend, FurMark 1x 280X 1080p 4x AA |
The SilverStone ST45SF V3.0 powered my test setup with no issues.
Fan
The atmosphere pusher here is a 92 x 15mm 7-bladed fan. Note that the silver rectangle on the bottom blade is a piece of reflector tape for the non-contact tachometer.
And interestingly (at least to a manufacturing dork like myself), Globe Fan is turning the ejector pin marks from a defect into a feature by imprinting their logo with one pin, and a recycling symbol with the other.
On the ST30SF V2.0, the fan model is a Globe Fan S0921512M. It runs at 12V, 0.23A, and features an enhanced sleeve bearing marketed as “Duro” bearings.
The fan “curve” for this model shows it has a wide RPM range, starting from 500RPM at 2.9V up to almost 2600RPM at 12V.
The ST4SF V3.0 features a higher-RPM model variant, the Globe Fan S0921512H, with a slightly higher max amperage of 0.30A.
The -H fan in the 450W is about 200RPM higher across the board compared to the -M in the 300W.
Fan Controller
There’s not much to say about the fan controller on these units, since they feature an always-on fan with a simple temperature-based control. This is the same as the previous ST45SF V2.0, but it is a deviation from the original 300W. The ST30SF V1.0 featured a semi-passive fan controller, so in a sense the new version is a downgrade in that regard.
After the criticism from the hardcore SFF community regarding the semi-fanless behavior of the SX650-G and SX500-LG, I’ve noticed a trend with SilverStone SFF power supplies, where if they can’t implement a more sophisticated controller like those seen in the SX700-LPT and SX800-LTI, they are avoiding semi-passive behavior. For example, the SX550 (review coming Soon™), as well as the upcoming SX500-G and SX650-G all have always-on fans.
While this may seem like a lazy way out, the reality is that implementing a well-behaved semi-passive fan controller is both non-trivial (extra R&D and testing) and adds to the expense of the unit (extra circuitry and temp/load sensing). And as an owner of both a SX600-G and SX500-LG, I personally agree with this approach, I’d rather have an always-on fan than a flawed semi-passive implementation.
Protections
OTP was tested on both units by using a blow dryer to artificially raise the internal temperature. Both units shut down when heated like this, as they are supposed to.
According to SilverStone’s specifications these units also feature Over Current, Over Voltage, Short Circuit, Over Power, and Under Voltage protections. The last two are new to these revisions, their predecessors did not feature them.
Noise
I’ll start with the good: both units are fairly unobtrusive at idle and low loads, with no significant bearing noise, coil whine, or fan hum. With an open-air setup from a little over a meter away, both units are audible at idle in a very quiet environment, but not annoyingly by any means, and the 300W in particular being just noticeable over ambient. In a living room setup, with the PSU stuffed inside a HTPC case across the room, neither should be very audible at low loads, but unless you need the wattage, I’d recommend the 300W due to the lower starting RPM.
When pushed close to their full rated wattage though, these are not quiet by any means. In fact, I’d say they’re pretty loud. The ST45SF V3.0 was particularly bad, where I measured the fan at almost 2500RPM at 415W AC draw, the highest fan speed I’ve measured in any of my PSU reviews thus far. This was in open air at less than the full rated power also, so I imagine in a poorly ventilated case it could easily hit the full 2800RPM the fan is capable of.
The main reason for this is the rated efficiency of these two power supplies, or rather the lack thereof. Both of these are only 80 PLUS Bronze-rated, which means 82% efficiency at 100% load when running at 115V AC input, and for the 450W that works out to 99W of waste heat at full power! I mentioned in the conclusion for the SilverStone Titanium-rated 800W that more efficiency doesn’t necessarily make financial sense, but here’s a great example of the practical benefit of higher PSU efficiency. When both are at full load, the SX800-LTI is doing almost double the wattage of the ST45SF V3.0, yet it is still generating less waste heat than the 450W, and the fan curve reflects this.
Internals
I’m not really qualified so say anything about the internal layout or build quality, but even to a layman it should be obvious that both the ST30SF V2.0 and ST45SF V3.0 are based off the same platform, the OEM for which is Sirfa/High Power. The 450W features a larger primary cap, what look to be a few beefier transformers, and one more section of heatsink, but otherwise looks identical to the 300W.
Capacitors are a mix of Nippon Chemicon and Teapo, with the exception of the primary cap on the 300W, which is a Nichicon. Nippon Chemicon and Nichicon are Japanese brands, and generally considered first-tier, with the Teapo considered a second-tier capacitor brand, though still respectable. Luckily, all the caps that I can see are rated for 105°C despite the price point, because these units run quite hot due to the relatively low efficiency.
Conclusion
The SilverStone ST30SF V2.0 and ST45SF V3.0 are budget SFX units, and this shows in their feature set. They’re non-modular, but with the short lengths and relatively few number of cables, the wiring is quite manageable. They have always-on fans and only have Bronze-rated efficiency, but at idle they are still capable of fairly quiet operation, though load noise levels are another matter.
So if you want a SFX power supply to run a high-end build quietly while gaming, then look elsewhere. But for those on a budget who are just looking to power low-end to mid-range hardware, and noise at full load isn’t as much of a concern, then these entry-level SFX units from SilverStone are hard to beat. The ST30SF V2.0 is currently $50 with a $5 rebate and the ST45SF V3.0 is $60 and also has a $5 rebate.
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Review samples provided by SilverStone.
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