Energy efficient power supplies

[Sebastian]

Hey All,

It's been awhile, but I have a question in regards to being frugal and computers. So I thought MMM would be the best place to ask. Since I've been far more conscious of my power consumption I've come to notice that I'm always turning off my desktop because it uses so much damn power. I'm trying to look for something that uses a lot less power so I can actually enjoy using my desktop again!

Now I know part of it has to do with what I'm running overall, but frankly the only game I play is like 20 years old. So I'm not hooking up multiple video cards and running ridiculous stuff.

Does anyone have any recommendations for energy efficient power supplies?

Thanks!

[slugline]

The most cost-efficient way to go would be to simply set a timer in your operating system's power settings to put the system in sleep mode after a few minutes of inactivity.

Can you tell what brand/model is in your system now? If you do decide to swap it out, you could look for a PS that claims "80 Plus" efficiency from a top-tier brand like Antec or PC Power and Cooling. I'm not sure your "payback" period would be worth it though.

[Regisque]

The power supply isn't really a significant power draw on its own. The computer is drawing a certain amount of power and the power supply basically adds some level of inefficiency on top of that. You can get an 80+ gold supply for a basic computer for around 60 bucks but the difference will probably not be that significant.

80+ Gold power supplies have an efficiency of 90% at a usual loading while the lowest ranking has 80% at the same level so you're looking at a 10% improvement. Assuming you're running a basic computer and drawing around 250 watts you're going to be saving .025 kWh for each hour you use the computer. To pay back the initial $60 investment you're going to need to run the computer for 20000 hours.

But all that aside if would like some recommendations for good quality power supplies that run efficiently Corsair, Seasonic, and EVGA are great brands with good track records and here's a link to some of their supplies ranked by efficiency. https://pcpartpicker.com/parts/power-supply/#e=6,5,4,2,1&W=80,500&sort=a4&page=1&m=11,14,71

[Guses]

There has been trememdous increases in computing power/watt in the last few years.

If your desktop is particularly old, it may make sense to upgrade to a new (to you) gently used 2-3 year old system and sell what you have.

Without knowing your specs, it is hard to say if that would be a worthwhile avenue.

A big culprit of power usage can be your screen. Make sure it auto-turns off after a while.
 

[Sebastian]

Thanks for the replies! I build my own computers :) It's probably 4-5 years old now, but I think I had put in a 600watt cosair if I remember correctly. It doesn't really seem like the payoff would be worth it at this point so I guess I'll just get the sleep mode going a little quicker.

[cars+FIRE]

I never actually did the math, but have always assumed that laptops should use significantly less power than desktops.

If your game truly is "20 years old" you don't need the computing power of a high end desktop or laptop.

Of course a laptop with equivalent specs will cost more than a desktop, but if you're somehow able to get out of your desktop + peripherals and into a laptop without any big startup cost, maybe that could work?

I've been using a laptop as my primary computer/HTPC for quite some time, as I'm not a gamer and modern computers have more than enough horsepower for the type of stuff I do.

[ketchup]

Keep your current PSU until there's a problem (might be a while; I've never had a PSU younger than 10 years crap out), and make your next one a more efficient one if you're concerned about it.  As has been said, the power usage differential makes upgrading for the sake of it not worth it.

Also, laptops use quite a bit less power in general (especially recent ones), so keep that in mind going forward too.

[HipGnosis]

Is your monitor CRT or LCD?
LCD's take considerably less power.

[BDWW]

I'm curious what your exact specs are. If you bought a 600 watt PSU, I assume you bought a fairly burly graphics card with it.

If you aren't concerned about modern games, I'd consider getting a lower end card. Heck if your card is 5 years old, a lower/low-midrange card might be just as fast or faster, and draw significantly less power.  You can get a really low end card for ~$25 bucks. I'd just try to evaluate what you need for your games and see what you can get away with.

The payback is probably not there for anything else.

[Sid Hoffman]

Thanks for the replies! I build my own computers :) It's probably 4-5 years old now, but I think I had put in a 600watt cosair if I remember correctly.

First things first, a power supply is like a car's engine.  Just because you have 600 watts doesn't mean you're using it all the time.  In fact it doesn't even mean you've ever used anywhere near that much.  For example, does a 600hp Corvette need 600hp when idling in traffic?  Nope.  Is it making 600hp when cruising at 75mph on the highway?  Nope.

Same with computers.  For myself, I build a midrange gaming PC for about $1000 two summers ago.  At the time, an i5-4670k, GTX760, and SSD along with the supporting stuff was considered midrange at least.  At any rate, so many sites tell you that you need 600+ watts for a gaming PC.  I went with a Gold rated Seasonic 450w power supply instead.  Sure enough, even with being overclocked and everything it draws a max of 250 watts while gaming and about 46 watts at idle, such as watching Netflix or writing on messageboards like this one.

Still, I suspend mine every time it's not in use and it's set to go to sleep on its own after an hour of inactivity.  Sleep mode is easy to engage (just hit the power button, assuming you have it set up in the power options) and to wake from sleep takes only a second or two.  The SSD actually is a big part of the performance, but even when I used mechanical hard drives, waking up from sleep was a quick affair compared to a cold boot.

[RWD]

I've been really happy with my Seasonic power supplies. Efficient, quiet, and reliable. That said, I wouldn't replace power supplies unless one died.

[Sid Hoffman]

I've been really happy with my Seasonic power supplies. Efficient, quiet, and reliable. That said, I wouldn't replace power supplies unless one died.

They're generally regarded as the best of the best.  I have one in a PC that's been rebuilt 4 times and is now my sister in-law's computer.  It has a Seasonic S12-600 from ~2007 and is still chugging along just fine.  You pay a premium up front, but the odds of failure are a lot lower and you may be able to do like I did and transfer that power supply forward for multiple PC builds if you overhaul every 2-3 years or so.  The current trend is moving away from high power consumption CPUs and GPUs, which means whatever you buy that's sufficient today may be sufficient basically forever, as the future products will simply have equal or lower power consumption than what's available today.

[gimp]

The more efficient ones are not much more expensive than less efficient ones. I have a ... 1200W? 1300W? PSU with something like 90% efficiency.

Of course it's a bit overkill, but it's good for a PSU to be overkill for a computer. Unlike a 600hp corvette, the PSU actually loses capability over time, the LS9 or LT4 motor really does not :)

[TomTX]

The more efficient ones are not much more expensive than less efficient ones. I have a ... 1200W? 1300W? PSU with something like 90% efficiency.

Of course it's a bit overkill, but it's good for a PSU to be overkill for a computer. Unlike a 600hp corvette, the PSU actually loses capability over time, the LS9 or LT4 motor really does not :)

1200w is insane overkill unless you're running 4 top-end video cards, etc.

[Syonyk]

I assure you, you cannot run 4 high end GPUs on a lowly 1200W PSU.  For a quad setup, you're looking at a 1500W PSU, minimum, and probably 1800+ if you want to get some decent efficiency out of it.

For 8 GPUs, you're at 2500W wall draw with Titan X, 3000+ with AMD cards.

:)

To the OP:

Either don't worry about it and shut down/sleep your machine when it's not in use, or build a new machine.  I upgraded from my desktop to an iMac, and the power savings are immense, but that doesn't mean you'll save money on it.  The difference between an 80% and a 95% PSU, on typical desktop loads, just isn't much.

[BlueMR2]

In my experience, I wouldn't even worry about it.  I went from running 2 large desktops systems to running a small laptop and a tablet and the electrical savings are well, not even noticeable.  Completely lost in the noise of our normal variation.  We're pretty low power users to begin with, so I expected it to be obvious.  Doing the experiment though says it's not worth spending money on and expecting a payback...

[Singularity]

Thanks for the replies! I build my own computers :) It's probably 4-5 years old now, but I think I had put in a 600watt cosair if I remember correctly.

First things first, a power supply is like a car's engine.  Just because you have 600 watts doesn't mean you're using it all the time.  In fact it doesn't even mean you've ever used anywhere near that much.  For example, does a 600hp Corvette need 600hp when idling in traffic?  Nope.  Is it making 600hp when cruising at 75mph on the highway?  Nope.

Same with computers.  For myself, I build a midrange gaming PC for about $1000 two summers ago.  At the time, an i5-4670k, GTX760, and SSD along with the supporting stuff was considered midrange at least.  At any rate, so many sites tell you that you need 600+ watts for a gaming PC.  I went with a Gold rated Seasonic 450w power supply instead.  Sure enough, even with being overclocked and everything it draws a max of 250 watts while gaming and about 46 watts at idle, such as watching Netflix or writing on messageboards like this one.

Still, I suspend mine every time it's not in use and it's set to go to sleep on its own after an hour of inactivity.  Sleep mode is easy to engage (just hit the power button, assuming you have it set up in the power options) and to wake from sleep takes only a second or two.  The SSD actually is a big part of the performance, but even when I used mechanical hard drives, waking up from sleep was a quick affair compared to a cold boot.

Agreed that Sleep mode/suspend to disk is one of the biggest wins.  You really need to get data on your power draw.  Use a Kill-a-watt device or a nice AVR UPS to get a rough idea.  Newer CPUs and motherboards are significantly more power efficient.  Some LCD/LED monitors can use 25% of the power of older models as well.  Seasonic and some models of Corsair are top picks for reliable tightly in spec power delivery. 

Power Supplies are also more efficient in the middle of their ratings.  Also move to 230volt input for more efficiency.

P.S. An max power draw test stressing your video card and doing AVX math should draw more than 250 watts.  The CPU alone can draw over 140 watts depending on overclock. 

[Sid Hoffman]

P.S. An max power draw test stressing your video card and doing AVX math should draw more than 250 watts.  The CPU alone can draw over 140 watts depending on overclock.

Yes, I have OCCT, Furmark, orthos, and a handful of other synthetic load tools.  You'll note I said "gaming" not synthetic load.  All I'm getting at is that for normal PC components a 1000-1200+ watt PSU is like buying a GMC 3500HD turbodiesel dually so you can tow a single car trailer with an all-up weight of 5000 pounds.  That's a truck made for towing 23,000 pounds.  Sure, you can tow a 5000 pound trailer with it, same as you can power 250-300 watts of gaming components with a 1200 watt PSU.  It works all right, but it will cost you more up front and costs a little more over time, too.

I'm a big proponent of right-sizing.  You can see in graphs like this one which list the AC power draw (which is higher than the DC output of a PSU) that even gaming with a high end CPU and overclocked GTX 970 records around 306 watts.  That's at the upper end of what you would even call a midrange gaming system.  CPU for the graph below is a power-hungry i7-4960X @ 4.2GHz with 4 x 8GB DDR3 DIMMs.



That's an awful lot of horsepower to still only draw 306 at the plug, which translates into maybe 275 watts DC being delivered by the PSU.  The OP seems to be interested in maximizing efficiency.  I'd just encourage right-sizing the PSU, as you can save tens or even a hundred dollars or more by right-sizing that PSU.  Plus, it will then be working close to its efficiency range.

[RWD]

P.S. An max power draw test stressing your video card and doing AVX math should draw more than 250 watts.  The CPU alone can draw over 140 watts depending on overclock.

Yes, I have OCCT, Furmark, orthos, and a handful of other synthetic load tools.  You'll note I said "gaming" not synthetic load.  All I'm getting at is that for normal PC components a 1000-1200+ watt PSU is like buying a GMC 3500HD turbodiesel dually so you can tow a single car trailer with an all-up weight of 5000 pounds.  That's a truck made for towing 23,000 pounds.  Sure, you can tow a 5000 pound trailer with it, same as you can power 250-300 watts of gaming components with a 1200 watt PSU.  It works all right, but it will cost you more up front and costs a little more over time, too.

I'm a big proponent of right-sizing.  You can see in graphs like this one which list the AC power draw (which is higher than the DC output of a PSU) that even gaming with a high end CPU and overclocked GTX 970 records around 306 watts.  That's at the upper end of what you would even call a midrange gaming system.  CPU for the graph below is a power-hungry i7-4960X @ 4.2GHz with 4 x 8GB DDR3 DIMMs.



That's an awful lot of horsepower to still only draw 306 at the plug, which translates into maybe 275 watts DC being delivered by the PSU.  The OP seems to be interested in maximizing efficiency.  I'd just encourage right-sizing the PSU, as you can save tens or even a hundred dollars or more by right-sizing that PSU.  Plus, it will then be working close to its efficiency range.

I agree that buying too much wattage is a waste. Also, power supplies are less efficient if you're only running a small percentage of their maximum load. But keep in mind that they are also more efficient if you aren't using maximum power. It varies slightly by PSU, but somewhere around 50% load is usually optimal. For example, this Seasonic provides maximum efficiency at 56% load:
http://www.silentpcreview.com/article1297-page3.html

So for something that you expect to draw 275 watts you should probably choose a ~490 watt power supply.

[sleepyguy]

honestly if you're running something not even remotely GPU/CPU hungry (which I assume you are cause you said it's old), then go get yourself one of those PC boxes that run Windows 81./10.  Yeah it'll cost more (not much more than a highly efficent 85+ gold psu) but they are super duper efficient with wattage and you won't feel bad leaving them on 24/7.  Then donate your old PC.

Something like this.

http://www.gearbest.com/tv-box-mini-pc/pp_194424.html