PSU wattage?

[MajorGoob]

So I did the highly suggested "Power Supply Wattage Calculator" and it said 474 watts. I want to go with a 550 watt PSU because there are some REALLY good quality 550 watt ones on sale. Should I go for the 550 or stick with the 600 I was originally going to get?

[Cryosec]

Go with the 550W, there won't be problems

[79wjd]

@MajorGoob what PSUs are you looking at and what's the rest of your hardware? 

[Xaring]

So, a bronze PSU has a 80% efficiency, your system real watt usage might be 474, but the PSU needs a 20% headroom, so 474/0.8=592.5W from the wall. You will need a 600W PSU (Really those 592 will only be under extremely high loads, but it might happen. 

[79wjd]

2 minutes ago, Xaring said:

So, a bronze PSU has a 80% efficiency, your system real watt usage might be 474, but the PSU needs a 20% headroom, so 474/0.8=592.5W from the wall. You will need a 600W PSU (Really those 592 will only be under extremely high loads, but it might happen. 

No.

 

The rating of a PSU isn't how much power it can pull from the wall, it's how much power it can deliver to the system. A 550w psu is capabale of delivering up to 550w to the system (while pulling up to 600w+ from the wall). 

[MajorGoob]

6 minutes ago, djdwosk97 said:

@MajorGoob what PSUs are you looking at and what's the rest of your hardware? 

Fractal Design Integra M. I feel like I see ads for them all the time and have heard good things about Fractal. I also love Sweden which is what originally caught my attention with the company.

[Xaring]

6 minutes ago, djdwosk97 said:

No.

 

The rating of a PSU isn't how much power it can pull from the wall, it's how much power it can deliver to the system. A 550w psu is capabale of delivering up to 550w to the system (while pulling up to 600w+ from the wall). 

Yup, read back on it, if it is certified with a 80Plus certification does deliver the marked wattage  Im too used to OEM PSU that mark 500W and deliver 380W...

[MajorGoob]

Just now, Xaring said:

Yup, read back on it, if it is certified with a 80Plus certification does deliver the marked wattage  Im too used to OEM PSU that mark 500W and deliver 380W...

Yep. Certain Cheapo power supplies have a "Peak" rating. Which means if you feel like a pyrotechnics show, use this power supply at 500 watts. I just don't know how much overhead I should have as I am using an AMD R9 380 4 gig, with an AMD FX 8300. Both of which are fairly power hungry little boogers.

[79wjd]

 

5 minutes ago, Xaring said:

Yup, read back on it, if it is certified with a 80Plus certification does deliver the marked wattage  Im too used to OEM PSU that mark 500W and deliver 380W...

That's because your particular unit (and low tier units in general) is only designed to deliver part of its power over the 12v rail (in your case, about 30amps). 

 

2 minutes ago, MajorGoob said:

Yep. Certain Cheapo power supplies have a "Peak" rating. Which means if you feel like a pyrotechnics show, use this power supply at 500 watts. I just don't know how much overhead I should have as I am using an AMD R9 380 4 gig, with an AMD FX 8300. Both of which are fairly power hungry little boogers.

The 380 isn't that power hungry. But 550w is more than enough. 

 

But the Integra M is actually pretty low tier. 

[Xaring]

2 minutes ago, MajorGoob said:

Yep. Certain Cheapo power supplies have a "Peak" rating. Which means if you feel like a pyrotechnics show, use this power supply at 500 watts. I just don't know how much overhead I should have as I am using an AMD R9 380 4 gig, with an AMD FX 8300. Both of which are fairly power hungry little boogers.

The wattage calculator looks at worst case situations if you configure corectly, (add a little overclock on CPU and GPU) and go with whatever works best  So in this case 550W will suffice. The only reason you might want a 600W one is for a better efficiency curve

[MajorGoob]

2 minutes ago, djdwosk97 said:

 

That's because your particular unit (and low tier units in general) is only designed to deliver part of its power over the 12v rail (in your case, about 30amps). 

 

The 380 isn't that power hungry. But 550w is more than enough. 

 

But the Integra M is actually pretty low tier. 

Thanks! Just what I needed.

[STRMfrmXMN]

1 hour ago, Xaring said:

So, a bronze PSU has a 80% efficiency, your system real watt usage might be 474, but the PSU needs a 20% headroom, so 474/0.8=592.5W from the wall. You will need a 600W PSU (Really those 592 will only be under extremely high loads, but it might happen. 

That isn't how 80+ efficiency works at all. We have a guide pinned on this subforum that explains it. It's also in my signature m.

 

1 hour ago, MajorGoob said:

So I did the highly suggested "Power Supply Wattage Calculator" and it said 474 watts. I want to go with a 550 watt PSU because there are some REALLY good quality 550 watt ones on sale. Should I go for the 550 or stick with the 600 I was originally going to get?

Calculators are pretty much just random bullshit generators. What are the specs of the system you're powering? If you have one GPU there's little chance it's using more than 350W with overclocked hardware out the wazoo.

[MajorGoob]

2 minutes ago, STRMfrmXMN said:

That isn't how 80+ efficiency works at all. We have a guide pinned on this subforum that explains it. It's also in my signature m.

 

Calculators are pretty much just random bullshit generators. What are the specs of the system you're powering? If you have one GPU there's little chance it's using more than 350W with overclocked hardware out the wazoo.

AMD Fx-8300 overclocked to somewhere around 4 gigaherts. An XFX AMD R9 380 4gb. AMD 970 mobo. And 16 gigs of 1866 RAM. SSD boot drive and one Terabyte HDD. And then of course the nearly negligible things. 3 ish fans, CRYORIG cpu cooler, mouse and keyboard, etc.

[STRMfrmXMN]

Just now, MajorGoob said:

AMD Fx-8300 overclocked to somewhere around 4 gigaherts. An XFX AMD R9 380 4gb. AMD 970 mobo. And 16 gigs of 1866 RAM. SSD boot drive and one Terabyte HDD. And then of course the nearly negligible things. 3 ish fans, CRYORIG cpu cooler, mouse and keyboard, etc.

So around 300W under max overclocked load, that's about what you can expect. A 550W unit, assuming it's of decent quality, will do fine.

[MajorGoob]

1 minute ago, STRMfrmXMN said:

So around 300W under max overclocked load, that's about what you can expect. A 550W unit, assuming it's of decent quality, will do fine.

So what do you think about the Corsair CX series? The weird white colored ones are the ones im looking at. As far as I can tell there is no way to differentiate between the Green CX PSUs and the White CX psus.

[STRMfrmXMN]

2 minutes ago, MajorGoob said:

So what do you think about the Corsair CX series? The weird white colored ones are the ones im looking at. As far as I can tell there is no way to differentiate between the Green CX PSUs and the White CX psus.

The white ones are a fairly substantial step up in quality so they're a good unit compared to the old green ones which had a colored reputation, to keep things short. For your system a CX550 is good.

[MajorGoob]

1 minute ago, STRMfrmXMN said:

The white ones are a fairly substantial step up in quality so they're a good unit compared to the old green ones which had a colored reputation, to keep things short. For your system a CX550 is good.

Thanks. I love how it always takes 30 minutes of different opinions to come to the same conclusion. Seriously, if someone from the 1850s came here today, the hardest thing for them to believe is that we have a small rectangle in our pocket that gives us access to every piece of information known to mankind, and we use it to get into arguments with strangers, and watch videos of cats... 

[STRMfrmXMN]

2 minutes ago, MajorGoob said:

Thanks. I love how it always takes 30 minutes of different opinions to come to the same conclusion. Seriously, if someone from the 1850s came here today, the hardest thing for them to believe is that we have a small rectangle in our pocket that gives us access to every piece of information known to mankind, and we use it to get into arguments with strangers, and watch videos of cats... 

And how we've domesticated such weird animals, amirite?

 

Have fun with your new PSU!