PSU weak/strong

[jerryshardware]

Hello,

My following question looks like more than it is.
What I know: The PSU should not be too weak, and give a PC not less power than the PC needs.

My question is: Is it also possible, that the PSU is too strong, and gives the
PC too much power?

Would a PSU, which is more powerful than required,
damage the PC?

for example: a PC which needs a 550W PSU -> could I use a 750W PSU for it without any problems?

Or should the PSU have the exact required power -> neither less NOR more?

When choosing a PSU, should I only look for the Watts (in fact, I do not know what Watt means, but the more W, the
stronger it is, right? ) ?

Please answer me, I am kind of new to these things, so I have to gain knowledge about it.
Thank you, I am happy of every single reply .

 

[Ajay57]

Jerry you ask a good question, why because you will have many different opinions from the members here. This i stress is my own personnel view is try to get the best quality PSU you can afford. And a higher Wattage than you really need overall, by the way the system will only draw the power it needs. I.E. if you have like me a 850w PSU and your PC needs say 500w then that is what it will take. But the other side of the coin so to speak is if you have big PSU and you only draw say 50% of its capacity. In most cases your output would cleaner and more stable, because of less heat and stress on the components. But as i already stated it really depends on the QUALITY of the PSU! AJ.

P.S. The ones i would say are some of the best are Seasonic,Corsair and others there is a OC Guide if you wish to look at it!

 

[Bobnova]

Having a PSU that can put out 1000w doesn't mean it will put out 1000w.
The PSU will be less efficient running at <10% of its rated power, but it won't hurt it at all.
Running it over 100% of its rated power can cause Bad Things, so that is to be avoided.
Ideally you would have a PSU and system combination that used ~85% of the PSU's juice at full load. The actual efficiency difference on a modern PSU is awfully small though, not really worth worrying about.

IMO the only meaningful reason not to buy a far too large for your system PSU is your wallet.

A "Watt" is a measure of power, you find Watts by multiplying Voltage by Amperage.
Add time to it (Watt-Hour, or KiloWattHour) and you have a measure of energy.


Personally I'm running a 77w CPU and a 250w GPU, though at idle those numbers are more like 5w and 25w at most. Maybe 100w total system draw at idle and 350w at full load. PSU wise, I'm using a 1000w unit.
In my case it's because I sold my previous unit and this one was the most efficient unit I had around that I have reviewed. I have a 500w unit I'll swap in once I've reviewed it, but right now it's still in its box.

 

[Oklahoma Wolf]

Having a PSU that can put out 1000w doesn't mean it will put out 1000w.
The PSU will be less efficient running at <10% of its rated power, but it won't hurt it at all.

Exactly. Why, you could even have a 1500W EVGA unit running a rig with only one video card and a Sandy Bridge

A PSU only puts out as much power as is required to do the job. It's best to try and figure out what you need first, so you can size the PSU appropriately to get it running inside its optimum efficiency range.

 

[jerryshardware]

Thank you guys.
So theoretically and practically I could use a for example 1000W PSU for a 500W system.
This would not let any component make more heat than usual, and would not stress any component more than usual ?

 

[Bobnova]

Nope, it'd be just fine.

OW's system has a 1500w PSU and draws maybe 350w on a bad day. Mine draws about the same with the 1kw unit.

 

[ssjwizard]

This would not let any component make more heat than usual, and would not stress any component more than usual ?

Nope, they will all run fine and dandy. Though for most modern systems 750W PSU is overkill but it definitely gives you room to upgrade later! The big thing is finding a QUALITY unit. Not all 750W PSUs can push that rating. There are a handfull of 750W units out there that will catch fire ~400W.

We have a list of recommended PSUs HERE

 

[Ajay57]

I think the two members above ^^ would hopefully agree with me your last post is some what "OTT meaning over the top!" Yes you can run that way if you wish, but i would not because its just to much power. A good quality 850w gold or Platinum rated PSU would do the job and also would have power enough to run 2 cards in SLI/Xfire as well. AJ.

 

[EarthDog]

I think the two members above ^^ would hopefully agree with me your last post is some what "OTT meaning over the top!" Yes you can run that way if you wish, but i would not because its just to much power. A good quality 850w gold or Platinum rated PSU would do the job and also would have power enough to run 2 cards in SLI/Xfire as well. AJ.

I wont speak for them.. however, I tell people a QUALITY 550W PSU is fine for any single GPU/CPU both overclocked (and it is with reasonable overclocks, meaning air/water ambient). I mean, Im running a 3570K @ 4.5GHz and a 680 overclocked to 1250/1800 and the fan doesnt even spin up on my unit. I cant imagine Im pulling more than 400W at the wall...

There is no point, IMO, if you will not go more than one card, to get more than that. If there is a possibility, then I say 750W+.

 

[SMOKEU]

The system will only draw as much current as it needs.

 

[pistola]

Hi guys i need some guidance on PSU's aswell i just ordered this budget gaming PC from ibuypower (i don't build from scratch cause i suck and am lazy)

I was wondering if the PSU is sufficient/ good enough im on a budget obviously so as long as it good enough to do some OCing nothing crazy maybe 3.8-4.0 . In the future i might add some RAM or get a New GPU maybe add a HDD or SDD just need a little headroom i guess. It not too late too change the PSU i just don't want to spend money pointlessly. I really dont't know much about PSU's any other suggestions on the rig are appreciated thanks gentlemen .

1 x Case (NZXT Vulcan Gaming Case - Black))
1 x Processor (Intel® Core™ i5-3570K Processor (4x 3.40GHz/6MB L3 Cache) - Intel Core i5-3570K))
1 x Motherboard (Gigabyte GA-Z77M-D3H -- 1x PCI-E 3.0 x16, Lucid Virtu Technology))
1 x Memory (8 GB [4 GB X2] DDR3-1600 Memory Module - G.Skill Ripjaws X))
1 x Video Card (AMD Radeon HD 7950 - 3GB - Single Card))
1 x Power Supply (650 Watt -- NZXT HALE82N-SI / 80+ Bronze))
1 x Processor Cooling (Liquid CPU Cooling System w/ 92mm Radiator [Intel]))
1 x Primary Hard Drive (1 TB HARD DRIVE -- 32M Cache, 7200 RPM, 6.0Gb/s - Single Drive))
1 x Optical Drive (24X Dual Format/Double Layer DVD±R/±RW + CD-R/RW Drive - Black))
1 x Sound Card (3D Premium Surround Sound Onboard))
1 x Network Card (Onboard LAN Network (Gb or 10/100)))

 

[EarthDog]

Plenty.

 

[Bobnova]

Yup, that's plenty of wattage.
I've reviewed the 550w and 750w flavors of that PSU. They're good units.

 

[pistola]

Plenty.

ok good to know thanks earthdog i was a bit lost on the PSU and hastily picked something it looked ok and it was on special.

 

[pistola]

Yup, that's plenty of wattage.
I've reviewed the 550w and 750w flavors of that PSU. They're good units.

lo agian good to hear because my crappy PSU sabotaged my last rig lol I was afraid it was going to happen again.

 

[jerryshardware]

Thanks to you all a lot.
By the way, does anyone of you know something about thermal pads?
I have already asked in some communities, also here, but nobody could answer all my questions.
Do I have to replace them (in my case the pad is on a memory chip on a graphics card)?
Are there good thermal pad brands?
Thank you all again.