# Typical lifespan of PSU?



## Jooo (Jun 30, 2011)

Hi, what is the typical lifespan of a PSU ?

I'm currently running my system with a six year old Nexus NX-4090 400watt psu.
I was running it earlier with 3 years old Delta 300W psu (I know the minium requirement for 5670 is 400watts), which has been working perfectly fine.
It is still working, I just had the Nexus lying around without use, so I thought 400watt psu would be better choise than 300watt psu for temporary use, especially as I'm running it quite near the limit.

My system specs are:
Radeon HD5670 1GB graphics card
Phenom II x4 965BE
4GB DDR2 800MHz ram
2HDD's, blu-ray drive
120mm led fan, two regular 120mm fans
Two 30cm cold cathode lights.

I am getting a new PSU, but I need to wait a month before I can afford it.
I'm just asking if I should use the 300-watt Delta psu (was using it yesterday), or stay using the 400-watt Nexus psu(using it right now)


----------



## Tyree (May 10, 2009)

There is no set lifespan for PSU's or any other hardware. They last 'til they die and hopefully die alone. The Delta is probably better quality than the Nexus but I wouldn't trust either of the PSU's with any build.
You should be at 550W minimum with a good quality PSU to help insure against damage to your other components.


----------



## Jooo (Jun 30, 2011)

Yes, I'm probably going to get the XFX Core Edition 550W.
But I cant afford it right now, so I'm wondering which one is better for temporary use.


----------



## Tyree (May 10, 2009)

Using either is taking a chance with the life of your other components. 
IMO, the Delta is a better quality but also has less advertised power.
The choice is yours.


----------



## Johnny1982 (Oct 15, 2010)

I just hope your components will hold out on that 6 year old PSU before you can afford another one, otherwise you risk having to replace other components in the event that the Nexus PSU fails. 

Having said that your PSU does not have enough AMPS on the 12v rail for a decent PCI-E card.


----------



## MattCharman (Oct 28, 2011)

Jooo said:


> Hi, what is the typical lifespan of a PSU ?


The value you want is the "MTBF" - Mean Time Between Failures. It is an average life expectancy of the product according to the manufacturer. It's not always on the box, so sometimes you have to dig around to find it. It's an average, so some last longer, some shorter, but at least it gives you a starting point!

The Nexus NX-4000 400Watt power supply has a typical lifespan of 11.4 years under continuous use at 25C according to the manufacturers documentation.

If you run your system hotter than that, lifespan may well decrease, but they haven't provided any data at higher temps (some do, some don't). Typically a PSU lifespan will drop by very roughly 20% for every 10C until you start hitting around 60C, so if you're running at 45C it's probably more like 7 years continuous.

It's a continuous use figure however, so if you don't leave your PC on 24/7, 6 years isn't really that old, as long as it's been well looked after and kept clean. If you used it 12 hours a day, and kept it cool at 25C, it might even last almost 23 years!


As for requirements, the 400W is ok. The Delta 300W will work, but it will struggle; its life will be massively decreased because you're pulling more off the 12V than it's designed for, so I wouldn't risk it. I really wouldn't want to go lower than the 400W.

The XFX 550W is over what the system needs, but not massively so, and would be a good choice IMHO as it gives you some room to add other bits. If you don't plan to add anything, the 400W should be ok.

Personally I'd stick with the 400W at the moment - prices on PSUs are not great right now, and you can often pick up a bargain in January/February, so you may well find your XFX reduced at that time.


----------



## Tyree (May 10, 2009)

I would say that life expectancy calculation is fine in theory but, as we are all aware, not in the real world.
You need to be at 550W with a good quality PSU (i.e. the XFX) to properly and safely power your hardware.
Simple math - ATI says 400W minimum - Add 30% for degradation to help insure sufficient quality power as your PSU ages=520W.
The SeaSonic M12II 520W is about $90. The XFX 550W (SeaSonic Built) is $76 making it the best bang for buck in your required power range.


----------



## ReviverSoft (Nov 30, 2009)

Just a quick tidbit:



> Life span is usually measured in mean time between failures (MTBF). Higher MTBF ratings are preferable for longer device life and reliability. *Quality construction consisting of industrial grade electrical components* and/or a larger or higher speed fan can help to contribute to a higher MTBF rating by *keeping critical components cool*, thus preventing the unit from overheating. Overheating is a major cause of PSU failure. MTBF value of 100,000 hours (about 11 years continuous operation) is not uncommon.


In general, the lifespan on paper varies from 50,000 hours for the average power supply up to 100,000 hours for high quality power supplies. 

However, there is always a chance of the PSU failing, more so with a low-quality one.


----------

