Long-lived Aluminum Electrolytic Capacitor - Apparently, higher quality Japanese aluminum electrolytic capacitors are used for greater reliability and stable performance. More common China-made capacitors must have been used before, as is typical of most PSUs. There have been incidents of motherboard and PSU brands being affected by leaking capcitors sourced from China starting from ~2 years ago.
Opening up the either the S12-600 or S12-500, one is greeted with an impressively large pair of unique heatsinks. They are both dense and quite large, with a double row of fins. They resemble teeth on a coarse comb. The basic design originated in the Super Tornado; it is a clever way to maximize cooling surface area in the reduced height available to components due to the 1" depth of the 12cm fan.
1. VOLTAGE REGULATION was excellent, within -/+2% on all lines at all test loads, except for the 3.17V reading at full powerful, which was -4% off. The low and high voltage seen on each of the main lines is shown below. Unless otherwise noted, the lowest voltage recorded were at the highest loads.
+12V: 11.91 to 12.12
+5V: 4.90 to 5.02
+3.3V: 3.17 to 3.32
2. EFFICIENCY was excellent, as expected of these 80 PLUS certified power supplies. The efficiency / power output ratio curve was quite flat from below 20% of rated load all the up close to maximum power. The flat 87% efficiency obtained from 200W to 400W is most impressive. In practical applications, these PSUs will be very tough to beat for energy efficiency, with their combination of high AC/DC conversion efficiency and active PFC.
3. POWER FACTOR was just about perfect across the power range.
4. TEMPERATURE: The high efficiency combined with the large heatsinks and effective airflow in these PSUs to provide the best in / out air temperature rise recorded in our PSU tests. At all power loads of 250W or lower, the temperature rise was only +3°C. It gradually rose to +7°C at full power load. This compares very favorably with many PSUs that hit +7~10°C in / out temperature rise by 50% load. It is not unusual for 15°C to be exceeded at full power loads. This means that the S12-500 and S12-600 are very effectively cooled and overheating should rarely be a cause for concern.
5. FAN, FAN CONTROLLER and NOISE: The test environment is live, so readings are higher than would be obtained in an anechoic chamber readings, due to reflections and reinforcement of sound waves off the walls, ceiling and floor.
The start SPL of 21 dBA/1m was 3 dBA higher than that measured on the original version of the fan-cooled PSU champion (for noise), the S12-430. But it was still extremely quiet. The new Adda-fan equipped 430 is only one decibel quieter. (See postcript to S12-430 eview.) The first hint of fan noise increase was heard (and measured) at 150W output or ~31°C intake temperature. The overall noise stayed quite modest until past the 250W load. When listened up close. the dual ball bearing fan has a bit of the typical ball-bearing chatter, but it is very subdued, and based on our recollection, much quieter than the earlier 5-blade Yate Loon fans first used in these models.
NOTE: Since the original review, SPCR has made their test environment more stringent to meet the efficiency requirements of Energy Star's 80 Plus program. Thus, the original efficiency range of 77% to 87% has been corrected to a range of 75.1% to 82% and does not meet the 80 Plus standards.
80 PLUS is described as "a national buy-down program for desktop computers and desktop-derived servers that contain highly efficient power supplies." The program invites submissions of PSUs, which are tested, and if the units pass, they become 80 PLUS approved. The test is quite tough: It calls for 80% or better efficiency at 20%, 50% and 100% of a PSU's rated power output. When a system integrator uses any 80 PLUS certified PSUs in systems, they can receive rebates through the 80 PLUS program, ostensibly to offset the initial higher cost of these highly efficient PSUs.
Using CEM DT-8850 digital sound meter
• ~ 10 cm (4 inches) away 37 dBA
• < 1cm 39.8 dBA
The 12cm fan turns at a lazy ~650 RPM at idle and reaches a high of ~1,050 RPM after 30 min of Prime95, any water cooling radiator fan or CPU fan or case fan will overcome the noise from this power supply.
When it comes to “which power supply should I buy?” a frequent question raised in many review forums, there are only a few names you are going to hear out of dozens of brand name. The people “in the know” may well only have less than a handful that they will consider using in their personal rigs. It is a welcome sign to seeing Seasonic, a well established power supply manufacturer with ISO certifications comes into the enthusiasts market allowing excellent choice in the crowded yet still with a good chance to grow in share of market when all the "right stuffs" are there.
Currently using a thermaltake toughpower 750W on my main gaming system, and very happy with it so far. While the volts are a bit low, the deviation is less than 0.05V, and it doesn't even budge 0.01V when doing disk, GPU and CPU benches simultaneously.
Even with the 140mm fan drawing air from the case, the air coming out of it is not very warm, especially considering earlier PSU's, so the efficiency rating of up to 85% can't be far off. The size also means it's slower and quiter. The only fans I hear are the stock AM2 fan and 7950GX2 fan, which will be remedied as soon as there's waterblocks for them available here.
The PSU comes highly recommended, even if the price is a bit steep.