[gentoo-user] Sizing up power supplies [was: switching adapter - power supply]

[Alan Mackenzie]

Hello, Dale.

Apologies to Thelma for hi-jacking the thread so early, but this point
is too interesting just to pass over:

On Mon, Mar 20, 2017 at 12:57:00 -0500, Dale wrote:

[ .... ]

> I might add, when I buy power supplies for my puter rigs, I try to buy
> one that will only be loaded at around 40 to 50%.

Do you mean 40 to 50% when the computer is going full blast (?like
building libreoffice, or something like that).

> One, it is lightly loaded relative to what it can handle.  Two, it
> will most likely handle heat better at those levels.  Third, it allows
> for upgrades, hard drive additions etc without having to buy another
> one.

Just how does one calculate the amount of power a box will use?
Processors proudly say "95W tdp", or whatever, but how much power does
RAM use, or the motherboard, or SDDs, or HDDs?

I'm anticipating building a new rig in the coming weeks/months
(depending on how soon the motherboard makers start producing Ryzen MBs
in quantity), and I'd be interested in getting an optimally sized PSU.
Most of the time, my PC is just idling along, with sporadic bursts of
activity like building libreoffice.

So how do I work out the electricity consumption of all these
components?

> I hope that info will help.

Thanks!

> Dale

-- 
Alan Mackenzie (Nuremberg, Germany).