Pros, Cons And Final Verdict
SilverStone takes the dimensions of its PSUs very seriously. To be more specific, it tries hard to offer the smallest possible PSUs in every wattage category. All three Platinum Strider models are only 14cm long, and like all high-end SilverStone PSUs, they're fully modular as well. Sirfa uses quality components in its design; only the Teapo polymer caps sound a little out of place (and not because of their reliability, since Teapo enjoys a good name, but mostly because in a $145 750W PSU, we expect to find only Japanese capacitors).
The competition is stiff in this category, with many PSUs sporting high-quality caps. Fortunately, polymer caps last much longer than electrolytic ones, so there's really no reason for us to ding SilverStone's score on this. Additionally, the ST75F-PT uses a high-quality bulk cap from Rubycon, which has a notably longer lifetime than the Chemi-Cons we often see from the competition (3000-hour versus 2000-hour lifetime). Lastly, the FDB fan ensures reliable operation. We're only missing a way to test the fan, since this PSU features a semi-passive mode that can't be manually deactivated.
As SilverStone claims, its ST75F-PT is the smallest Platinum-rated 750W PSU you can buy with fully modular cabling. Smaller dimensions make it harder to cool a PSU properly, so it's nice to see this unit not only operating efficiently, but also quietly. If you're after friendly acoustics and compact measurements, the ST75F-PT looks like a solid (albeit pricey) choice. Despite modest performance, it's at least highly efficient with excellent ripple suppression on the +12V rail.
One major weakness is the PSU's single EPS connector, which forces you to use an adapter for a second EPS or ATX12V connector if you want to power a high-end mainboard. A second downside is very low hold-up time. Although SilverStone used a high-quality bulk cap, its capacity is very low and cannot offer the minimum required hold-up time. And finally, the most significant drawback is a relatively short warranty. Given the price of this PSU and the number of competing offerings, three years of coverage just doesn't cut it. If SilverStone wants to keep up, it should offer at least a five-year warranty on this product and all of its other high-end PSUs.
Update 8/12/2012: SilverStone informed us that the warranty of this product has been increased to five years.