Mini-Itx Psu questions.

[Naganick]

Hello everyone.

I have yet to come across some definitive answers about the best way to calculate the amount of Wattage I need in my PSU, in addition to having enough amps.


I have the machine spec'd as such

P8Z77-I Deluxe
http://www.asus.com/Motherboards/Intel_Socket_1155/P8Z77I_DELUXE/#specifications

3770K
http://ark.intel.com/products/65523
Max TDP of 77W

hd 6950
http://msi.com/product/vga/R6950-Twin-Frozr-III-Power-Edition-OC.html#?div=Specification

3 fans, 1 7200 Seagate drive (6w)

The gpu is where I am getting mixed messages.

I have been looking at reviews and OEM power consumption.
They range from 200w (oem) up too 290w (highest test seen)

I was trying to build on this PSU.
http://www.silverstonetek.com/product.php?pid=342&area=en
450w gold cert.

In the documentation it shows it is capable of running a 6950.
http://www.silverstonetek.com/downloads/PSU/GPU-supportlist.pdf

All overclocking aside...

Does anyone this I will be able to run the system with this Psu? Or am I in for a rough ride...

Thanks for your time~

using the power calculator I am in the clear (sticky form the forums) even on amps... w/v=a

 

[airdeano]

ive calculated 340-350watt with your reciepe.
the 6950 refence card requires 38amps on the 12v rail. the MSI TF cards are not
reference cards.. more power phases, dual PWM fan, and other power drains. but
lets pretend your sporting a ref card first.

with the calc compared to the 444watt supply thats 79% of the total watts available.
add to that, the supply shows to be only 88% efficient at that loaded rate.

easy math..
88% of 444watts is 391watts, you are needing 350watts (100% load). if you
fart, you'll be tight short on watts... or cutting it very close.
my general rule is 150% of total load times 1.5 and this should give you efficiency
and headroom.
so your rig should have a PSU rated 525watts on the 12v rail. not 444watts.

so add to the mix, your non-reference carded and i'd say your short some watts
of reliable.

airdeano