PSU wattage

[Nicnac]

Hey,

quick question: If I have a good 300W psu that i know can actually deliver 300W (unlike most cheap PSUs that fry themselves at about halfway) why would it still be ill-advised to run a let's say 75W CPU and a 150W gpu on it? I mean I would have plenty of headroom (if I don't decide to put a bunch of drives and other cards in).... still 500W are the minimum recommendation for 150W graphics cards. Why is that? Is it simply because you can't trust 300W PSUs?

 

[Billy_Mays]

It's because they don't want you to fry your whole system so they have the precautions in place because they don't know what you have in your system 

[Mr_Random_Guy]

They don't know what cpu you have, how many drives you have, how reputable your psu may be

Really they're just covering themselves

[Guest]

5 minutes ago, Nicnac said:

Hey,

quick question: If I have a good 300W psu that i know can actually deliver 300W (unlike most cheap PSUs that fry themselves at about halfway) why would it still be ill-advised to run a let's say 75W CPU and a 150W gpu on it? I mean I would have plenty of headroom (if I don't decide to put a bunch of drives and other cards in).... still 500W are the minimum recommendation for 150W graphics cards. Why is that? Is it simply because you can't trust 300W PSUs?

 

because a 450w costs a bit more and allows room for overclocking compnents, low wattage psu are bad in price/wattage ratio

[Ramaddil]

Plus PSU's are more efficient with power delivery when they are not used to capacity.

 

http://www.corsair.com/en-us/blog/2012/august/80-plus-platinum-what-does-it-mean-and-what-is-the-benefit-to-me

[STRMfrmXMN]

2 hours ago, Nicnac said:

Hey,

quick question: If I have a good 300W psu that i know can actually deliver 300W (unlike most cheap PSUs that fry themselves at about halfway) why would it still be ill-advised to run a let's say 75W CPU and a 150W gpu on it? I mean I would have plenty of headroom (if I don't decide to put a bunch of drives and other cards in).... still 500W are the minimum recommendation for 150W graphics cards. Why is that? Is it simply because you can't trust 300W PSUs?

 

The manufacturer gives a recommendation to cover themselves. Generally, once you buy into higher wattage mass-market PSUs you can find ones of higher quality. So AMD might recommend a 500W PSU for an RX 570 even though the GPU could run cozy on a CX450M with a 5960X or similar. 

 

The TL;DR is that Nvidia and AMD want to sell to consumers who can actually safely utilize the hardware they're selling.