Overkill PSUs

WuMyster

WuMyster

WuMyster

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Well I got the general consensus in the watercooling area saying theres no such thing as overkill but with PSUs im hearing the problem of efficiency etc.

What im wondering is if people can confirm if you can overkill on PSUs. My thoughts are just "future proofing" on the PSU department so that If i ever do go for quad titans or whatever it will be, then ill be set.

If a raise in my electricity bill and I bare say it, contributing to the greenhouse gases then im fine with that. Just wondering whether or not by running a PSU with more than enough wattage will damage itself or the components will not draw efficient amounts of wattage.
 
Ah, so this "will up your electricity bill" is a shambles?
No component or PSU damage by running it at lower watts?
 
As far as I'm aware it uses only what it needs, especially since the power a computer is using will change and not be current.
 
Right. Thats good to know. Ill go research into this more. Looking to get a 1000W as ill definitely do a quad gpu setup, just not this generation or the next!
 
Found an answer and ill post it here if anyone is in the same thought process as me!

Will using a 1000W power supply on my low-end system fry anything?
No. A power supply will only deliver as much power as the system needs, and no more. If you plug a system that needs 100W into a 1000W PSU, the PSU will deliver 100W and no more. PSU performance does drop off somewhat at very low percentages of its total wattage, so you may get poor efficiency, but your system will not be harmed.
 
All the comments about it only delivering what your PC needs are true (taking efficiency into account) so it won't be overkill or wasteful in that way.

The only other way to look at it is that you'll be paying more than you need to for the PSU initially, which some may consider wasteful, but if you plan to use the extra capacity in the future then it's not all bad.

Providing it lasts that long of course :D There seem to be a lot of "PSU failed" topics about atm.
 
The only thing to know really is efficiency. If you have a 1KW PSU and you draw 400W max, then it's not going to run at 80% efficiency (if it's a 80+ certified PSU).

But yeah it won't draw 1KW :)
 
So basically, as its not efficient, then im just wasting money on my electricity bill right?
If so, im completely fine with that :P
 
WuMyster said:
So basically, as its not efficient, then im just wasting money on my electricity bill right?
If so, im completely fine with that :P
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In a manner of speaking yeah, it may be pulling more from the wall than your system needs but honestly it's not worth considering for a single machine. Maybe you'll spend an extra £5 a year, you won't feel it :p
 
I would say buy the best you can afford. If your spending a decent amount on one, it will have a long warranty and should last you through several builds.

I used to run a 620w as previously i was told it would be ok for crossfire (4870's at the time) but found when wanting to run 6970's it wasnt enough. In the end I opted for an AX1200i knowing I wont ever need more power and with a long warranty (7 years) should last me ages.
 
Thats exactly my approach. I dont wanna buy a 750W now to drive 7950's and then have to buy a 1000W later down the line for quad cards.
1000w PSUs (80+ plats) arent that expensive IMO. Ill definitely look for ones with long warranty. Corsairs customer support is superb but Im doubting their new AX series.
 
There's an efficiency curve. A PSU rated for 200W is quite likely to top 85% efficient at 100W load. So it might use 110W from the wall.

One rated for 2kW will be less efficient, as it's further from design point. Maybe 150W from the wall.

Far more important is the internal electronics. A £60, 1000W power supply is almost certainly crap. A £60, 400W power supply is probably rather good. So spending more money will get you a better power supply, but looking for a really high wattage at low price will get you a piece of **** that breaks and savages the rest of your system.

The one in my computer is only 860W, but cost £150. Probably bronze certified, definitely isn't gold. It's been good, but I'll probably get a better one for the next system.
 
Its a bad idea to buy something like a 1000w 80plus gold power supply if you're only going to be using it for something like a single gtx 670 system.

Reason? Your paying extra for the 80 gold capabilities but because its being used in a system that doesn't require much power you will be getting sub 80 gold efficiency most of the time. Not only does it cost more but will give you performance similar to a much cheaper lower wattage and lower 80plus rated power supply.. it will actually give worse efficiency than something like a 500w 80 plus bronze while idle.

If you only have one 7950 now in my opinion the best option would be a decent 800w at most. This will be plenty for any dual gpu system wether it be 7950's or titans. Would also handle 3 7950's since you have a low power cpu, but probably wouldn't want to overclock them much. It will also be cheaper and give better efficiency.
 
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WuMyster said:
Well I got the general consensus in the watercooling area saying theres no such thing as overkill but with PSUs im hearing the problem of efficiency etc.

What im wondering is if people can confirm if you can overkill on PSUs. My thoughts are just "future proofing" on the PSU department so that If i ever do go for quad titans or whatever it will be, then ill be set.

If a raise in my electricity bill and I bare say it, contributing to the greenhouse gases then im fine with that. Just wondering whether or not by running a PSU with more than enough wattage will damage itself or the components will not draw efficient amounts of wattage.
Click to expand...

You need a 1500 watt PSU if you are going to run 4 Titans + hexcore CPU all overclocked and even then it is a pretty close call.

WuMyster said:
Right. Thats good to know. Ill go research into this more. Looking to get a 1000W as ill definitely do a quad gpu setup, just not this generation or the next!
Click to expand...

My two GTX 690s plus 3930k overclocked pull more than 1000 watts at the wall.

If you use dual GPU cards like the GTX 690/HD 7990 the minimum PSU unit you should use is 1200 watts, if you are going to use 4 individual cards like Titans or GTX 780s then you really need a 1500 watt PSU.

People will say "well that's on X79" this is true but that is the platform for multiple GPUs.

Even three Titans plus 3930k overclocked pull more than 1100 watts at the wall.
 
System will only draw what it needs.
However I think there are several reasons not to rush out and buy a 1.2KW PSU

1: With components becoming far more energy efficient, you are not 'future proofing' anything
2: PSUs operate most efficiently in a certain band of power draw, if you are under or over this band by a large amount you lose a small, but measurable amount of efficiency/money on power bills
3: These PSUs are usually expensive!
 
No doubt is a cheap 1000w PSU bad let alone a 100W one. Ill only be looking at the popular Corsair, Silverstone, XFX and Enermax ones.
As im reading all your helpful posts, im seeing that its all about efficiency. Not pulling enough wattage from the PSU will cause in a lower efficiency. Is this just about wasted wattage I will be taking?
 
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