25 replies to this topic

[Ori Klein]

Get a PSU around 15% higher than your system requirements so it can handle entropy better (matter degradation is of consideration, and your computer will start rebooting and cease normal operations once it is not properly supplied).
As the many electricians before me explained, if you overpower all that happens is that you draw more power from the grid, pay for it, and don't really use it. Due to the forces involved, your PSU just ends up being highly inefficient.

[Thorqemada]

Its never a fault ot have plenty of headroom - most PSUs have the best efficency around 30-70% power usage and good PSUs make up for bad Mainboards, so to have 30-50% headroom is total ok if you can afford it.

[VGLance]

Unless you have a build like mine, you're not going to need a >=1000 watt PSU. Here's a link to my build although I've added a few things to it like another 1TB HDD.

[Zombie Gandhi]

I'm sure it's been written somewhere in the thread, but simply; your PSU needs to power every piece of equipment. When ordering parts, check their power requirements (mobo and GPU, primarily). I once built a tower and ordered a new mobo/gpu, and made the noob mistake of not checking the required minimum power needed. Needless to say, I felt very silly, and had much nerd-rage.

[SakuranoSenshi]

Ori Klein, on 10 August 2012 - 03:23 AM, said:

Get a PSU around 15% higher than your system requirements so it can handle entropy better (matter degradation is of consideration, and your computer will start rebooting and cease normal operations once it is not properly supplied).
As the many electricians before me explained, if you overpower all that happens is that you draw more power from the grid, pay for it, and don't really use it. Due to the forces involved, your PSU just ends up being highly inefficient.

This sounds a lot like you don't realize that a 750 watt PSU supplying a system that only needs 300 watts will only draw 300 watts (well, actually it'll draw more because it's inefficient but I am coming to that). You don't waste any 'extra power'; it not a 'power supply unit' really it's a 240 volt (or 115 volt in USA) to 12 volt and 5 volt (sometimes others) transformer (which is why it is inefficient). If you did realize this, no worries, at least it makes it clear for anyone else.

PSUs are pretty inefficient until they hit about 75% output, from 50% and up you're doing okay, below that and you're just wasting power, as heat. All PSUs get hot, no matter what level of draw but there is a sweet spot, as it were (actually a curve) and you get there by drawing slightly less than 100% down to about 75%. For various reasons you don't want to buy such that you'll be very close to maximum output (not the least of which is that over time your power draw will tend to rise slightly and your PSU capacity will tend to drop slightly) but you definitely do not want to massive overspec either because you'll just be paying money to turn electricity into heat and then more money to vent that heat out of the system with your fans.

In practice, very few people (including a few people who swear that they do) need more than 750 watts. Most people, even with pretty respectable hardware could probably run on a 450 watt PSU and majority of 'power gamers' would be fine on 600 watts.

[Dymitry]

VGLance, on 14 August 2012 - 07:12 PM, said:

Unless you have a build like mine, you're not going to need a >=1000 watt PSU. Here's a link to my build although I've added a few things to it like another 1TB HDD.

Bragging, are we?