Seasonic Super Tornado 300W PSU Review


Power supplies are one of the most if not the most important choices you will make when you build a computer and here at we have reviewed a couple of good power supplies recently.

We remembered how our first Seasonic impression was. It did not fair well. The power wasn’t there. Seasonic contacted me on reviewing one of their new line of power supplies. Today we are going to be testing out the new Seasonic Super Tornado 300W PSU.

The Seasonc Super Tornado 300W PSU came in a new box design with a portfolio of Seasonic. Seasonic just opened a new branch in the USA and the portfolio showed off more about them. I was very impressed from what I read and hope this is the Seasonic I wanted to see before. The box design had various amounts of information and had a big picture of the unit. One of the things that were very cool to see was Seasonic claims that you will save money running this power supply.

Information all over the box


Features and Benefits:
* 120mm Cyclone Cooling Fan [>70CFM]. Double airflow with half the RPM & noise. Outperforms all dual-fan units on the market. Cools your system more quickly and quietly. Longer life span due to high CFM, lower RPM and strategic fan placement. * Smart & Silent Fan Control (S2FC). Silent enthusiast's best choice. Reduces noise without increasing temperature. Extends fan life by eliminating unnecessary rotation. Automatic temperature adjustment prevents manual errors. Optimum-balanced structure for strength and ventilation. Enhances airflow to solve thermal and noise problems. Improves working power factor from the typical 50% to 99%. Improves energy utilization to cut your bill in half. Environment friendly technology. * Super High Efficiency (up to 80%). Cool, quiet, reliable & energy saving. Surpasses the market average efficiency of 68%. Saves 15% energy; runs 40% cooler. Optimal solution for low noise, thermal & high reliability. * Forward Converter. Advanced design for reliable power More reliable.More efficient. Eliminates manual selector. Eliminates potentially harmful mistakes. * Cable Management Kit [Dr. Cable]. Make your PC tidy & neat. Tidy up messy wires quickly. Eases access to the connectors. Smoothes airflow to improve cooling. * 3-Year Mfg Warranty. Our commitment to superior quality.

  • Meet Intel ATX Ver 2.03 spec and AMD recommended.
  • Forward converter circuit.
  • High efficiency and reliability. Active PFC, 220VAC full load @ 0.99 typical. Power efficiency 80%
  • Low ripple and noise less than 1%.
  • Super low noise fan control
  • Acoustics 25.8dBA typical at 70W
  • Short circuit protection and over power protection.
  • 100% hi-pot test.
  • 100% burn-in, high temperature cycled on/off.
  • AC input voltage, 100-240V, 5A @ 50/60Hz.
  • DC output voltage, +3.3V @ 28A, +5V @ 30A, +12V @ 18A, -12V @ 0.8A, +5Vsb @ 2A.
  • Power Connectors; 7X 4PIN(5.25"), 2x 4PIN(3.5") 1x 4PIN(Pentium 4), 1x 6PIN, 1X 20Pin, 1x 3Pin(fan)
  • Dr. Cable Kit include split tube, cable mount, and cable tie.
  • EMI/RFI compliance.
  • Safety compliance, UL, VDE, cUL, FDD, and CB.
  • MTBF >100,000 hours @ 25c
  • 340W Peak
As you can see by the specifications, the 120mm can flow up up to 70CFM of air.  As it is a 300W unit, some of the DC output voltages are low. The unit can last up to 100,000 hours which is around 9-10 years of life.  The max power you can get from this unit is 340W.

What is included with the Super Tornado is the following:


  • 300W Power Supply
  • Manual
  • Power Cord
  • Screws
  • Dr. Cable

As you can see, the power supply has a huge 120mm fan that is used to dissipate the hot air out of the system. This is actually pretty good because 120mm fans provide more surface area thus pulling more air out than the regular 80mm power supply fan solutions. Hopefully this can become a new trend.  All this comes at very low sound. Almost silent at 22dBA in regular temperatures and when the Seasonic sense that the temperatures are higher on load the fan speeds up automatically. This is almost standard in most power supplies today. This is why the PSU is an Active PFC power supply.

The enclosure and it's wires!  However they are short for my tastes.

As you can see, the wires have no sleeving on the ATX cable and the cables have a spaghetti wire effect. That’s where the cable management system, dubbed Dr.Cable (looming) that Seasonic has provided will come into play. This is a good idea by providing some cable loom to clean up the look of the cables.

Dr. Cable

The rear of the power supply is very unique. There is a honeycomb design that allows air to flow outwards. The 120mm fan makes good amounts of air exit through the rear. You have better cooling than 80mm cooling solutions. I’m a big fan of this. The rear has the power switch present. There is no need for the voltage switch because the Seasonic automatically detects if you are using the 115V or 240V standard.

The rear honeycomb design.  It's effective though.

I was curious to see how the power supply looked inside so I opened it up voided the warranty…oh well.

  • A small movie of how silent this unit is.  (The camera's speaker is crackly, I know) 56KB, WMP 9 Required


Testing will consist of running the power supply for two days and recording the idle voltages and load voltages. The system configuration is the same exact system I use everyday in the System Setup page.


Idle (30 mins)
Load (Toast 5 mins)
+12V = 11.90
+12V = 11.855
+5V = 5.05
+5V = 5.00
-12V = -12.75
-12V = -12.85
-5V = 0
-5V = 0

The power supply gave out good voltage rails and there was little fluctuation  There was some in the 12V line though.  There was one thing that made me confused.  There was no -5V rail.  None at all at load or idle.  Not even when I re-connected the P4 connector to the mainboard.  Maybe the P4 connector is dead or non-working?  I hope this is just my unit that was affected.  Mysteriously the system was stable and had no problems.  The -12V rail is a little high though.  This is a good indication of maybe more power is needed.


The Seasonic Super Tornado 300W power supply is a good power supply with very good voltage readings and that is very quiet. The included Dr. Cable gives you the chance to make your system a little tidier. Although the power supply isn’t very good looking I still feel that this power supply is what I was looking for in Seasonic. I love the fact that a 120mm fan is present and takes the role of cooling.   It's a much better solution to 80mm fans ...Period.  There was one major problem though. Maybe it was only my unit but I could not get a –5V reading no matter how many times I tried to re-connect everything. Mysteriously, everything was stable though. Very weird. I hope this is only my unit that was affected.  The new Seasonic lacks features that are very new to power supplies on the market now with the introduction of SATA power connectors.  I have noticed that these are the trend in new power supplies.  Nothing will go against the Seasonic in the final rating but I just would like you to know that we will be looking for these in future PSU reviews. 

At the prices below in Alternative Pricing info, it's a bit high for a 300W unit.  There are other similarly priced units that have higher wattage that were reviewed here and those are a better deal for the wattage it comes with.  However, if you do buy this unit, it does it's job well if you don't have the -5V reading problem as I have.  I see potential but I'd say it's a close call if you should buy.  I don't think you should for the price.

I rate the Seasonic Super Tornado 300W Power supply a…


Pros and Cons

+ 120mm cooling and silent!
+ Voltage readings
+ Dr. Cable
- Plain looking with short cables
- Mysterious –5V reading of 0 and high -12V rail.
- Expensive for only 300W from the prices below compared to other units

I would like to thank Seasonic for making this review possible.

Alternative pricing:

Update (Aug 25): Seasonic has informed me that this is the new ATX 12V Version 1.3.  Intel has removed the use for any -5V.  That is why in the voltage rails in the specifications there is no -5V.  I must have missed that and wanted everyone to know.  Please check for more information on the new ATX v.1.3 spec.  I will update more for you when I have more information. 

Update #2: Seasonic says Intel said that the -5V line is only used to power any ISA cards you may have.  However, since ISA is now obsolete it won't affect Intel or AMD based systems by not having the -5V line.  Please disregard anything I said about why did I get a 0 reading.  This is a new standard, that is the reason.  If you decide to pick this up, it's a good power supply.  I still stand by the price statement I made though. 


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