Good quality 400w psu enough for GTX 1070?

[Silver47]

Hello guys,

 I've got a SFX psu by BeQuiet! which is rated at 400w with 80+ Bronze efficiency. Its got all the usual safety features which are usually found in good quality powersupplies, safety against over-currents, over- and under-voltages, short circuits, and overloads. 

I know that Nvidia recommends at least a 500w unit but most psu calculators on the internet say that my system will be drawing about 330w under load. I understand that this isn't an ideal situation and that most powersupplies like to run at about 50% load since they are most efficient there, but I don't intend to run it this way forever.

 

So as long as the maximum system power draw won't exceed the max rated wattage of the psu I should be good, right? I only want to know if it will outright fail if I turn it on the first time, I don't intend to run it this way for long. Couple of days or as long as its going to take for my new 650w psu to arrive.

 

Related question: I understand that it isn't a great idea to max out a powersupply, but generally it should mean its still technically safe, right? I mean if its rated at 400 watts by the manufacturer (and is of relatively good quality) it should be able to deliver 400 watts under any circumstances?

 

System specs (or at least whats important in terms of tdp):

 

i7 4770k, stock voltages, mild oc by multiplier only

z97 mini itx mainboard

2 x 8gb ddr3

gtx 1070

120mm aio cooler

2 x 120mm pwm fans

1 x 2,5" ssd

[kelvinhall05]

I mean, I wouldn't do it, but if it's only for a few days...sure.

[Silver47]

2 minutes ago, kelvinhall05 said:

I mean, I wouldn't do it,

Could you specify why exactly you wouldn't? Do you think this would overload the psu?

[kelvinhall05]

Just now, black0utm1rage said:

Could you specify why exactly you wouldn't? Do you think this would overload the psu?

Yeah, I think it could overload the PSU, especially when gaming.

 

I wouldn't game for a few days, or just not use your PC at all until your new PSU arrives.

[Stefan Payne]

1 hour ago, black0utm1rage said:

Hello guys,

 I've got a SFX psu by BeQuiet! which is rated at 400w with 80+ Bronze efficiency. 

Sorry, but that's not really a good PSU.

be quiet does good stuff in ATX but other form factors (TFX, SFX) not so much. Partly because its a Niche...

 

The Wattage isn't an issue, 400W is more than sufficient for that system, without OC of course. But The SFX Power is not really that good.

[Qwerty2323]

There are many reasons to get more psu W. 

Main one is related to cooling. If psu load is less than 50% many of modern ones wont use fan. Also with age psu ability to hold W decreases slightly.

I always recomend people not to save on 2 components: memory and psu. 

 

So 400W is enough but for safer and more silent preformance and longer lasting psu 500-550W is better choise.

[Stefan Payne]

37 minutes ago, Qwerty2323 said:

There are many reasons to get more psu W. 

Naa, not really...

 

37 minutes ago, Qwerty2323 said:

Main one is related to cooling. If psu load is less than 50% many of modern ones wont use fan. Also with age psu ability to hold W decreases slightly.

No

because within the same plattform, PSU often use the same heatsink.

And higher wattage units often come with higher speed fans.

 

So assuming that a higher wattage PSU will be quieter is just wrong. 

You have to look at the unit you want to buy and decide with the data you got. 

 

NEVER EVER assume anything!

 

Because I know a series where the ~550W PSU is OK, the ~650W thingy rather loud, the ~750W again at the level of the 550W. For whatever reason.

 

37 minutes ago, Qwerty2323 said:

I always recomend people not to save on 2 components: memory and psu. 

True but for the PSU you want Quality, not quantity.

 

Going from an EVGA B500 to a Bitfenix Formula 450W is an increase in quality, not quantity.

 

37 minutes ago, Qwerty2323 said:

So 400W is enough but for safer and more silent preformance and longer lasting psu 500-550W is better choise.

That is a wrong assumption. 

In some cases the 400W is the quietest of the series under any circumstance.

 

In some cases the 400W is the same as the 500W.

In some cases the 400W is the same as the 600W 

 

But with ~the same Heatsinks and ~the same efficiency, how can one be quieter than the other?? That is only possible if you allow one to get hotter than the other...

[Spotty]

2 hours ago, black0utm1rage said:

Couple of days or as long as its going to take for my new 650w psu to arrive.

Just wait a few days.
Have you already ordered the 650W PSU? What model is it?

[Guest]

2 hours ago, black0utm1rage said:

Couple of days or as long as its going to take for my new 650w psu to arrive.

 

Did you at least order a decent 650W PSU?

[Silver47]

On 15.9.2018 at 5:27 PM, jonnyGURU said:

Did you at least order a decent 650W PSU?

Ordered a Silverstone SX650-G, the review of which I actually looked up on your website prior to ordering! Hopefully this little bad boy will last me some time because it certainly wasn't cheap.

[Silver47]

On 15.9.2018 at 5:11 PM, Spotty said:

Just wait a few days.
Have you already ordered the 650W PSU? What model is it?

I'm running the system currently in a very Frankenstein manner with the enclosure open and my old Corsair TX650 sitting right beside it on the desk, powering the whole thing. I ordered a Silverstone SX650-G, which should nicely fit into my Silverstone SG05. Should arrive late today or early tomorrow.

[Silver47]

On 15.9.2018 at 4:10 PM, Stefan Payne said:

Sorry, but that's not really a good PSU.

be quiet does good stuff in ATX but other form factors (TFX, SFX) not so much. Partly because its a Niche...

Realized that too after looking up some in-depth specs. Decent, but hardly a high-end product. Has served me well though, never had any complaints.

[BigDamn]

You can run it that way, but I wouldn't game on it. If you kill your PSU you risk taking other components down with it. Run the 400w, but take it easy until the new PSU comes in.