When one wants to build a pc system from the ground up the very foundation of a long lasting and healthy system is a good power supply unit.
There are plenty of cheap power supplies in the market and as such why would anyone want one that costs almost as much as some cpu? The simple answer is that for a healthy and durable system you need a power supply unit (psu) that isn''t likely to melt after the warranty has expired.
With that preface what sets the Seasonic psu apart is that although it is rated at 430w it actually performs much like a 600w psu and that too at over 80% efficiency.
Unlike the cheaper psu on the market this is actually built by the original equipment manufacturer (oem) Seasonic. The most important thing here is Seasonic are very well regarded and personally having used both the 430w and 520w units I can see exactly why.
However the 430w does lack a high amp rating on the most important part of a psu - the 12v rail. Even so because the Seasonic psu uses a single rail it is more than capable of even powering the latest intel haswell and and amd fx cpus.
This is ideal for a mid ranged gaming pc that has a single dedicated graphics card, a few hard drives and dvd/blue ray devices. My intel i3 build which was made 3 years ago used the Seasonic 430w psu and it is still working flawlessly cool and quiet like the first time I bought it.
I would highly recommend spending a little extra to get this psu instead of a cheaper make like CIT with psu rated at 600w. In the long run you will save more on energy due to the efficiency and reliability and the fact that Seasonic provides 5 year warranty more than makes up for the price.
It you are asking yourself how can you spend less money when a psu cost 5-6 times more than a normal psu you probably don't know why these are so important right now, how much you save will depend probably even on how much your psu is old but it's probably time to put it away for the time being.
Sea Sonic S12II-430 is a psu for middle market, it has 430 watts power and is almost 80-85% efficient.
What is efficiency when it comes to psu ? Efficiency is how much the psu need to draw to let your computer component have the power they need, It's probably a little complicated to explain so I will go with an example:
If your pc uses 100 watts of power and you have a 60% psu you will use 140 watt of real power, the 40 you add are the wasted energy from 60 to 100%,if your pc uses 200 watt of power is probably using 280 real power and so on, with this new kind of device you will be able to save up to 20-25% more of energy wasted by your pc, keeping the world greener and spending less on your energy bills.
Seasonic is a very good brand, know for it's reliability as well as the ability to build very efficient psu, so you probably will get an excellent psu with this one that will last very long.
As I said before this psu is useful for the middle class casual user who does not require a very powerful video card or a very powerful processor, in this case you would need probably a much powerful psu.
The price is around 50-60 £ but saving up to a 20-25% on your pc energy will sure get your money back over time, especially if you keep your pc running 20-24 hours a day or you have a very powerful pc.
If you are asking yourself why the price is so high, the answer is easy, saving energy it's not an easy thing to archive and there are a lot of studies to be done and this technology it's relatively new to the market so the price will be high for some time.
You can find a list of 80% or more efficient psu in this website: http://www.80plus.org/manu/psu/manu_psu.htm this one is not linked because it's new and has yet to be linked however the website of seasonic claim it's very efficient and seen the reliability of the brand it probably is.