SilverStone has in its arsenal seven SFX and SFX-LG units, with the most affordable being the ST30SF, which currently has a price tag of $49.99 on Amazon. This might be an entry level unit, but that doesn't mean it shouldn't receive upgrades and fixes. On the contrary, we believe that mainstream products should be the ones gaining the most attention, because they're of great interest to the majority of users who just want something that works well and doesn't cost too much.
With this in mind, SilverStone released the second version (v2.0) of the ST30SF, which is equipped with a larger, quieter 92mm fan. These fans are the largest ones that SFX units can accommodate, and they manage to offer a more silent operation compared to 80mm fans because they're able to push the same amount of air at lower speeds.
More changes in the ST30SF v2.0 model include a lower temperature rating and the removal of the semi-passive operation. The v.2.0 model is rated at 40 ℃ for full power delivery, whereas the original model has a higher temperature rating, at 50 ℃. Moreover, the v2.0 unit has stronger +12V and 5VSB rails, but its minor rails are weaker.
We don't know why SilverStone actually degraded the performance of the v2.0 unit, with the lower temperature rating, but the company said that the v1.0 is suitable for NAS/storage-focused systems or industrial PCs (IPC) because of the increased tolerance to heat and the stronger minor rails, whereas the v2.0 model is better for home and gaming PCs because of the stronger +12V rail and the lower noise output.
Given the significant differences between those two versions, we can safely assume that the new version is based on a different platform, and for that matter it might be provided by another OEM; FSP makes the v1.0 unit. Enhance usually rates its platforms at 40 ℃. Finally, SilverStone hasn't cleared out whether both versions of the ST30SF will co-exist in the market, or if the v.2.0 model will completely replace the older one.
|SilverStone ST30SF v1.0 & v2.0Features & Specs|
|Max. DC Output||300 W|
|Efficiency||80 Plus Bronze|
|Operating temperature||0 °C ~ 40 °C(v2.0) 10 °C ~ 50 °C (v1.0)|
|Protections||Over Current Protection Over Voltage Protection Short Circuit Protection Over Power Protection (v2.0 only) Under Voltage Protection (v2.0 only)|
|Connectors||1 x 24 / 20-Pin motherboard connector（300mm）1 x 8 / 4-Pin EPS / ATX 12V connector（400mm）1 x 6-Pin PCIE connector（400mm）3 x SATA connector （300mm / 200mm / 100mm）2 x 4-Pin Peripheral connector （300mm / 200mm） 1 x 4-Pin Floppy connector（300mm / 200mm / 200mm）|
|Cooling||92 mm Fan (v2.0) 80 mm Fan (v1.0)|
|Semi-passive operation||No (v2.0) Yes (v1.0)|
|Dimensions||125 mm (W) x 63.5 mm (H) x 100 mm (D)|
|Weight||1.0 kg (v2.0) 0.8 kg (v1.0)|
|Noise Level||18 dBA minimum (v2.0)0 ~ 38 dBA (v1.0)|
|Price at time of review (excl. VAT)||$49.99|
According to SilverStone's official specs, the v1.0 unit doesn't have Over Power Protection (OPP), so we cannot recommend its purchase. The lack of OPP can easily lead to a broken PSU, or even worse--to a burnt PSU/system, under severe conditions. In addition, the absence of UVP means that the PSU won't shut down even under very high loads (for its max rated capacity), where the rails will drop well below the respective minimum-allowed voltage thresholds. Given the upgraded protection features, the stronger +12V rail, and the larger fan, the v2.0 looks to be the clear winner, despite the lower temperature rating.
SilverStone ST30SF V1.0 Power Specifications
|Max. Power||Amps||21||20||22||2.5||0. 5|
|Total Max. Power (W)||300 @ 50 °C|
SilverStone ST30SF V2.0 Power Specifications
|Total Max. Power (W)||300 @ 40 °C|
Decent PSUs will at least sense the primary side current and tie that into the error amplifier circuit to do per-pulse current limiting, which provides enough protection to prevent the PSU from self-destructing.
BTW, I have one of these with me from a Silverstone "surprise box" I got a few weeks ago, just popped it open to have a quick look. It is a cute little critter and has a completely different internal layout from the previous version. Nichicon primary cap, Chemi-con 5VSB output caps, Teapo SC TC just about everywhere else. Uses a Champion CM6806 combination APFC-PWM controller and a WT7527 monitoring IC.
I have blown many PSUs under overload conditions, even some that on papers at least had OCP and UVP.
Also, the ST30SFv2 uses DC-DC converters for 3.3V and 5V, which means that 3.3V and 5V power comes out of the 12V rail's OCP budget. That's another effective way of limiting output power. Unless the PSU has been poorly designed, its components should be nowhere near within a momentary peak or short circuit from self-destruction - the ATX power specification itself requires that PSUs gracefully handle those situations by shutting down. If you manage to destroy a PSU this way, then it isn't truly ATX-compliant.
According to the WT7527 spec sheet the UVP min. level at +12V is 10.3V, the typ. is 10.65 and only the max is 11.0. Even if we go with the max (11V) we are still far away from the 11.4V that the ATX spec (Revision 1.31) sets as minimum limit for this rail even under peak load (it used to allow 10% deviation in older revisions). According to my experience so far if you push hard a PSU and drop the +12V rail at 11.0, then it is a matter of minutes (or even seconds) till it blows sky high. Especially under high ambient temperatures.
OCP on the minor rails is typical and most units have it. OCP at +12V is something that not all PSUs have, or they just have it set very high in order to actually disable it. Also I don't agree that OCP at +12V is an effective way to protect the minor rails (in the unusual case that they don't have OCP), because if you have low load at +12V you can practically push way too high the minor rails and still keep the +12V rail in spec. The +12V FETs might be handle the load but this won't be necessarily the case for the minor rails' FETs.
The ATX spec (sec. 3.5) only requires, when it comes to protection features: OVP, SCP, NL, OCP and OTP. So if you go strictly with ATX you still don't have OPP and UVP. Furthermore, OPP and UVP need to configured properly to provide effective protection.
For you the lack of OPP might not be a big thing, however for me and my experience (>500 PSU evaluations so far) it is. Especially since last week I blew sky high a very expensive PSU because its OPP wasn't configured properly (was set too high). Actually I expect every PSU to be equipped with the necessary protection features. Also even if we take your worst scenario in mind, the destruction of a FET is still a major disaster for the average user. Moreover, when a component like a FET (or a bridge rectifier) dies, it will most likely take some more along with it.
In any case, I don't have anything else to comment on this matter and to be frank I don't even have the time to deal with it any more. But I do want all of my readers to be properly informed (and not misinformed).
It isn't UVP's job to protect the PSU against gross overload, that's the OCP/OTP/OPP and the primary side's per-cycle current limit's job. UVP/OVP are there to shut down the PSU in case the power supply loses regulation, such as a fault in a feedback circuit causing one of the outputs to drift grossly out of spec.