Quick PSU Question

[Aaron O'Brien]

Been using a Corsair HX620W PSU for about 3 years in a P4 system and just wanted to make sure it's OK to use it in a new i5 750 system I'm going to build.
There's nothing wrong with swapping it from P4 system to an i5 one is there? Will it still give correct power (and enough power)...?

New system spec:

i5 750
MSI P55-GD65
4870 1GB
4GB DDR3 1600MHZ
Samsung F1 320GB


Thanks.

[Domestic_Ginger]

Use an online power usage calculater such as antecs but they do not seem to have i5 on there. Plugging in an i7 920 comes out at 280W wi the rest of your system. As long as the i5 uses less power than an i7 and you have at least 30A ((280x120%)/12 just to be safe) on the 12V rail you should be okay.

You should also be working in the sweetspot for the highest efficiency of your PSU.

Someone please correct me if I am wrong.

[GoNz0]

according to capacitor aging you need to take 60% off the wattage, so in theory your on or past the limit if you follow antecs 20% reduction per year.

[woody_294]

Surely the capacitor ageing scenario is worst case, I'd like to try out an old PSU and see what the damage is. 60% loss sounds ridiculous. I've got an old 1980's PSU (not PC), although it's fairly high spec it's still good for 90% of the original value :s

[GoNz0]

it's not us, if you want to gamble all that new kit on a 3 year old PSU be our guest

you may be lucky, you may not.

you may get run over crossing the road, you may not.

just make sure you look left and right

[oolon]

according to capacitor aging you need to take 60% off the wattage, so in theory your on or past the limit if you follow antecs 20% reduction per year.

A 60% reduction is not a 20% reduction per year.

100 *.8 = 80
80 *.8 = 64
64 *.8 = 51.2

Giving a final of 51.2% not 40% of the original power remaining after 3 years.

Now doing it your way where your reducing the original power giving a PSU which can produce no power in 5 years your see the reductions are increasing in rate year on year.

1-(80/100) = .2 (20%)
1-(60/80) = .25 (25%)
1-(40/60) = .333 (33.3%)

Either way I think that the calculation is ridiculous, and just a way to scare people into buying new PSUs, 5-10% would be far more realistic.

[Domestic_Ginger]

Electrolytic capacitor aging. When used heavily or over an extended period of time (1+ years) a PSU will slowly lose some of its initial wattage capacity. We recommend you add 20% if you plan to keep your PSU for more than 1 year, or 25-30% for 24/7 usage and 1+ years.

nothing about 20%/year i think the 30% should be the figure used?

[oolon]

nothing about 20%/year i think the 30% should be the figure used?

Seems pretty reasonable, personally I always think power supplies are overrated, In the same way Hi-Fi makers used to quote Peek music power at some extreme level (probably measured in a reflective room too). I like to use PSUs at about 50% Capacity, which I believe gets plenty of margin for reductions over time, and the quoted figures not being realistic.