zer0 wrote:PeterH wrote:800W is a joke - if you don't have at least 2 high-end graphic cards and an overclocked processor.
I'm not sure that I agree that 800W is a joke. Without knowing the exact components, it's difficult to estimate the power supply that will be required. It's better to overestimate than to underestimate. If you factor in a powerful CPU, several sticks of RAM, a PCI-E GFX card, a couple or more HDDs, a couple of burners, add a soundcard, maybe another PCI peripheral (such as a wireless card?), fans, USB/Firewire/eSATA/Ethernet sockets -- it all adds up, especially if one takes into account that PSUs aren't 100% efficient, so you won't always get the power output that's shown

...from a german review of "Enermax Pro87+ EPG500AWT":
"Ansonsten gibt es keinerlei Bedenken dabei, dass man dieses 500 Watt Gerät mit einem Quad-Core und einer starken Grafikkarte wie der GTX 285 oder der HD 5870 betreiben kann. Das könnte man allerdings auch durchaus schon mit 400-450 Watt."
Translated: "Apart from that there are no doubts, that this 500W unit can be used for a quad-core and a powerful graphic card like GTX 285 or HD 5870. However this also could be done with 400-450W"
What hardware would you expect from Don? A high end gamer PC? A HD 5870? A 5750 uses more than 100W less - and is still overpowerd for Don. (Now we are at max 350W needed

800W
is a joke!)
Nowadays the need for power is normally overestimated. Don's system will use
maximum 100-150W in idle. This is 12-20% of 800W. Efficiency is getting quite bad at these low values.
And regarding efficiency: the power is specified for the secondary side: 800W specified delivers 800W, by input of maybe 1000W. (At 80% efficiency.)
But one thing is correct: cheap "generic" power supplies often do not deliver the power they promise -
that's bad! And maybe the reason to spend a bit more money.
And, as said before: efficiency is something that rents. By paying less for electricity over several years. (And it's good to feel a bit "green"

) I for my part plan will pay about 100€ - for 500W, but over 90% efficiency over a very wide area. (This is more than I will save - the rest is for the environment...)