Conclusions
I have to say this latest crop of PSUs has left me rather impressed. There really isn't a lemon in the bunch, and while some models offer lower noise levels, higher efficiencies, and superior overall value, all managed to deliver consistent DC voltages with relatively little AC ripple right up to the limits of their rated capacities. We shouldn't be surprised to see such a tight race, though. There may be eight different brands in this round-up, but in truth only a handful of companies actually manufacturer the PSUs we've tested today. That arrangement appears to have raised the bar for overall power supply quality, and that's a good thing, even if it does leave us with a collection of largely similar designs that offer near-equivalent performance.

Because these PSUs—particularly the best ones of the bunch—offer such similar performance, we've been forced to pick favorites more on the basis of value, warranty coverage, noise levels, and little perks like modular cables. We've summed up our thoughts on each PSU below.

BFG Tech ES-800 800W — The ES-800's lifetime warranty will no doubt impress some folks, but when it's gated by a 30-day registration requirement, it loses some appeal for me. I'm also not sure just how much value lifetime coverage adds over, for example, a five-year warranty. Fortunately, the ES-800 has more to offer, including great performance and very low noise levels. The ES-800 is quite frugal, as well, boasting some of the highest efficiencies we measured under lighter loads. And even though $165 online this is one of the more expensive PSUs of the bunch, we think it's TR Recommended material. Only relatively short cable reach—an important consideration for the larger enclosures that typically house systems that would require an 800W PSU—keeps the ES-800 from an Editor's Choice award.

ePower Thunder 650W — The Thunder delivered clean power like the rest of the pack, but this unit's $130 street price is simply too high in light of the competition. 650W isn't a whole lot of capacity for the price, and ePower's warranty is limited to three years when many of its rivals offer five years of coverage. The Thunder is quite loud, both at idle and under load, and its efficiency at 100% is the worst of the bunch. We do like the external SATA and USB power cable, but it's just not enough in the face of such strong competition.

Enermax PRO82+ 625W — The PRO82+ is a very quiet power supply, and it's one of only two in this round-up silent enough to dip below our noise level meter's decibel floor at idle. This Enermax is also the most efficient PSU we've ever tested with a modest 25% load, and is quite efficient overall. However, our enthusiasm for this unit is tempered by its $142 street price, which only gets you 625 watts and three years of warranty coverage. There are better values in this bunch.

Mushkin XP-800AP 800W — As the most expensive PSU in this round-up, our expectations were high for XP-800AP. On the surface, this unit has a lot to offer, including modular cables with a whopping four 8-pin PCIe power connectors, a five-year warranty, and the ability to switch between single and multiple 12V rails. However, Mushkin has some work to do on the efficiency front; the XP-800AP dipped below 80% efficiency at not only full capacity, but also at 75%. We'd also like to see lower idle noise levels from the XP-800AP.

OCZ EliteXStream 800W — You can see the PC Power & Cooling breeding in OCZ's new EliteXStream 800W, and that's a very good thing. This PSU maintained at least 82% efficiency across all our test loads, and with impressive output capacity, four 8-pin PCIe power connectors, serpentine cables that can handle upside-down and larger enclosures with aplomb, the EliteXStream is well equipped for demanding high-end systems. A surprisingly low $150 street price also makes the EliteXStream the cheapest 800W PSU in this round-up, bringing it perilously close to Editor's Choice distinction. However, a propensity for higher noise levels takes the EliteXStream down a notch; it'll have to settle for TR Recommended status, instead.

PC Power & Cooling Silencer 750W — The Silencer earned an Editor's Choice award a good 10 months ago, but is it still the daddy today? Much to our surprise, yes. The Silencer is still the quietest PSU in this class, with great power delivery and efficiency to boot. The competition has largely caught up on most fronts, and were the Silencer still selling for its original $170 asking price, we'd be less enthusiastic about it this time around. But the Silencer now costs just $140. When coupled with PC Power & Cooling's solid reputation and five-year warranty, that's good enough to retain its Editor's Choice crown.

Thermaltake Purepower RX 600W — With a $105 street price, the Purepower RX is a good $35 cheaper than the next-closest PSU in this round-up. It also features the lowest output rating, and more seriously, lacks 8-pin PCI Express power plugs. The RX is one of the loudest PSUs we tested, and its efficiency drops below 80% when pushed to the limit. However, Thermaltake does kick in a five-year warranty and modular cabling. Those factors don't make this our favorite of the bunch, but the Purepower is a good value.

Zalman ZM-750HP 750W — The ZM-750HP certainly lives up to its low-noise billing. More impressively, it's one of the most efficient PSUs in the pack, particularly with light loads. And it doesn't cost much, either; the ZM-750HP sells for just $145, which gets you clean power delivery and a huge bundle of modular cables. Unfortunately, those cables are poorly balanced. Zalman provides just two PCI Express connectors, only one of which can supply 8-pin power. That's going to be a limitation down the line, and when coupled with Zalman's three-year warranty, the ZM-750HP falls from Editor's Choice candidate to TR Recommended.

Singling out Editor's Choice winners is never easy, but PC Power & Cooling's Silencer successfully defends its belt as the best enthusiast PSU with just the right balance of performance, silence, and price. Our contenders from BFG, OCZ, and Zalman are great options, too, and if you're a stickler for warranty coverage, need long cables for a big enclosure, or want a modular design, one of 'em may be an even better choice for you than the Silencer.