Recommended Power Supplies |

"PLEASE NOTE that positioning on the list is determined primarily by the NOISE assessment, but this does not mean that a PSU is simply "better" than another because it is at a higher rank. In some cases, slightly higher noise but better power delivery may be a smarter compromise.

First Column: Manufacturer and model number

Q: Simply stands for quality. It is our assessment of the product's overall design, performance and build quality, not including noise. Ranked from 1-10, 10 being perfection. A number rank followed by "?" indicates we have not fully verified the assessment.

Noise: The amount and quality of noise the PSU makes with a typical load in a noise-optimized PC.

Ranked from 1-10:

10 = completely noiseless,
9 = effectively inaudible (usually this means <22 dBA@1m with a very smooth character and no hum, buzz or intermittent sonic effects)
5 = very quiet (~25 dBA@1m with a benign acoustic signature), and
1 = borderline quiet (~30 dBA@1m).
In this scale, 1 describes a usable PSU for a noise-reduced PC and quieter than the average PSU, which would have to fall into the negative numbers like -1, -2 and so on. We won't worry about that because we'll never recommend such noisy PSUs. Keep in mind that a noise-reduced PSU ranked at 1 may still be quieter than the other noise sources in many "standard" computers.
A number rank followed by "?" indicates we have not fully verified the assessment. Any audible coil buzzing is noted in the comments.

250W to 399W Q N Comments
Seasonic S12-330 & 380
(SS-330HB Active PFC) 7+ 8? The 330 is similar to S12-430 but the fan tends to get faster at slightly lower power than high power models. Newer sleeved version reviewed. The 380 was not officially tested but is used around the lab. It has the same size heatsinks as the 430, so the noise curve is pretty much identical to the 430. Aug 14/06.

Seasonic SS-300SFD 80 Plus 7 6 Highly efficient, powerful small form factor (SFX) PSU with Seasonic's excellent fan controller, slightly marred by a mediocre fan. Reviewed. Price: $60. Jan 3/06

400W+ Q N Comments
Corsair HX520/620 7+ 8+ Combines the modular cabling of the Seasonic M12 with the quieter single 120mm fan cooling configuration of the S12. Highly efficient. About the best balanced of Seasonic's current offerings (under its own brand or other brands.) Reviewed. Nov 17/06.

Seasonic S12 Energy+ 550/650 7+ 8+ Most efficient of Seasonic's current lineup, 80 Plus certified. The fan controller appears to be tweaked for lower noise even to very high power loads. Very quiet! Efficiency at very low loads (<65W) is no better than other models of similar rating. Reviewed. Oct 5/06.

Seasonic S12-430
(SS-430HB Active PFC) 7+ 8 Higher efficiency and very low noise (18~22 dBA@1m) up beyond fairly high power loads (~200W). ATX12V 2.0 compliance, high 12V current capability, excellent fan controller and quiet 12cm fan. Reviewed. Price: ~$100. April 5/05.

Seasonic S12-500 / 600
(SS-500/600HT Active PFC F3) 7+ 8 These 500W and 600W models have different circuitry than the lower powered S12s, slightly higher noise, and even higher efficiency. ATX12V 2.0 compliance, high 12V current capability, PCIe VGA connectors. Excellent fan controller. Reviewed. April 5/05.

Seasonic SS-400HT 80+
(SS-400HT Active PFC F3) 7+ 8 Same circuitry as in S12-500/600, this is a specially modified 80+ approved model that has higher efficiency especially at low loads. Same characteristics as the S12-500/600, otherwise. >85% max. efficiency is highest measured with newly calibrated test rig (v3). Probably very hard to find, as it is a non-retail product. Reviewed. Sept 2005.

Antec NeoHE 430
(430W ATX12V 2.2 Power Supply) 6 8 Middle model in series offering ~80% efficiency, detachable output cables, multiple 12V lines, APFC, auto-range AC input, quiet fan and intelligent fan controller. The 80mm fan is a very quiet ball-bearing Adda. Other models likely have similar acoustics and performance. Only a touch louder than the Seasonic S12-330, 380 & 430 models in actual use. Reviewed. High incompatibility issues appear to have been largely solved in the first quarter of 2006.

Seasonic M12-500/600/700
7+ 7+ Seasonic's first modular cable PSU line, the M12 also sports a secondary 60mm fan meant to address the problem of a hot spot which probably afflicts all 120mm fan designs. Very quiet at lower loads, even up to mid-200W, but once the 60mm fan starts, it never shuts off, which makes it a bit noisier than other Seasonics. The high power ratings make it clear it's aimed at gamers and performance nuts. Reviewed. Oct 11/06.

Be Quiet! Dark Power Pro 430
BQT P6-430W 7 7 Good quality, fairly high efficiency, low noise power supply only for 220VAC, competitive pricing. Availability limited to the EU. Reviewed. Oct 12/06.
Antec EarthWatts 430 7 7 It's basically an 80 Plus certified, non-detachable cable version of the NeoHE with a slightly louder fan. Still pretty quiet, even to a fairly high power load. Reviewed.

Zalman ZM460-APS
7 7 Based on the Fortron Green but with a better quality fan, this is the quietest PSU from Zalman yet. Pretty high efficiency, good cooling, and low noise to >200W load on our test bench make it a reasonable alternative to other top quiet recommendations. Reviewed $90~100. April 5, 2005.

Silverstone Element ST50EF-Plus 500W ATX12V v2.2 7 7 80 Plus certification and high efficiency competitive with the best, along with good acoustics to >250W load, and a nice fan controller, with a tendency to coil whine at very low loads (not unusual). Reviewed. Nov 17/06.

FSP Green PS FSP400-60GLN 7 6 Environmentally friendly power supply manufactured from recyclable and nontoxic materials offer high efficiency, stable power, good cooling and low noise with lower component density, all at a decent price. Availability seems spotty. Reviewed Price: ~$70. Jan 03/6.

Antec SmartPower 2-450
450W ATX12V 2.0 PSU 6 6 Dual 80mm push-pull cooling, with external fan that turns only at higher loads. Very quiet at low load, gets noisier more quickly with load than higher ranked models on this list. Good performance, good cooling, good efficiency. Reviewed. Price: ~$60. Sept 2005.

Enermax Noisetaker 701
7 5 A 600W model with high efficiency optimized for the new generation of very high power dual-VGA SLI systems. Not as quiet as the 475, but quiet considering power capability. Cables now much more flexible. Reviewed ~$170. April 5, 2005. NOTE: This unit has been replaced by an SLI-certified 701AX with PCIe connectors; it's not identical to the sample tested, but acoustics are said to be the same. Jan 3/06

FANLESS Q N Comments
Fanless PSUs are only recommended with strong cautions!

PicoPSU 7 9 The picoPSU is tiny — so tiny that 70 of them would fit inside the casing of a normal ATX power supply. Its footprint is that of a 20-pin ATX connector. It provides regulated +5V, +3.3V and +5VSB lines. It passes +12V from an external AC/DC power brick, which can be fanless. There are several models, rated for up to 120W, which is enough for many capable but power efficient systems these days. Perfect for silent mini PC projects. Reviewed. Price: $40~$55. Does not include AC/DC adapter, $30~$40. Aug 14/06

Silverstone ST30NF 7- 9 Heatpipes transfer the heat from internal heatsinks to the heavy external casing, which is essentially a 6-sized heatsink. Near 80% efficiency comparable to Seasonic Super and Enermax Noistake series, along with Active PFC. 12V current capability is adequate at 17~18A. LEDs indicate thermal condition. It also looks sleek and high tech in natural aluminum extrusion casing. Reviewed. Oct 18/04.

Silentmaxx Fanless 400W MX460-PFL01
7- 9- A higher power version of the Fortron Zen below, sold under a different label. It exhibited similar characteriscs and higher output. Not cheap for the rated power, but like the original, quite solid and silent. Reviewed. Price: $175. Aug 14/06

Fortron Zen FSP300-60GNF
300W ATX12V 2.0 7- 9- The highest efficiency of any fanless model (>84%) and second only to Seasonic's SS400HT "80 Plus" model, modest dual-12V current capability of 22A combined. Uses large internal heasinks and wide open mesh cover for convection cooling, which may be a bit suspect. Lower than usual price for fanless design. APFC, auto-range AC input. Reviewed. Price: <$100. Sept 2005

Antec Phantom 500 5+ 9- Adds low profile 80mm fan to intake side of the Phantom 350 and increases current limiting point. The fan kicks in only beyond ~35?C (200W load in our test setup), and is quiet at start, but ramps up audibly beyond. Good insurance against burning the PSU in a system with inadequate airflow, but once fan starts, it's not as quiet as the best fan-cooled PSUs. Reviewed. Price: ~$150. Sept 2005.

Less than 250W Q N Comments
Seasonic SS-200SFD 6 5 Very quiet 200W with sleeve-bearing fan in smaller case (SFX form factor) for Flex-ATX case, smart S2FC fan control for minimum noise. P4 12V connector. Good for custom small form factor systems (used in Breadbox PC) and as replacement for eMachine, HP, and other OEM PCs. 9/02. Price: ~$32

Shuttle SilentX 250 6 2 Quieter 250W PSU in long & narrow form factor replacement model for most Shuttle SFF systems. Uses two 40mm fans in push/pull config; they do ramp up under load. MSRP of $70 seems steep. Feb / 05