So i got my Kill-a-watt in the mail today. (Newegg got it to me 26 hours after I ordered it..wow). Plugged my power strip into it..which is currently just my computer, monitor, and a modem.

It idles at 150W, and gets up to 230 MAX while gaming. My computer specs are below.

I bought a 520W psu back when I was building this thing, and now i'm kinda pissed all those power calculators so grossly overestimated the computers power comsumpton! I mean, I even over clock it..the cpu AND gpu..and it still doesn't break 230..OH and thats including the monitor which doesn't even get powered by the psu.

Truth be told..i'm kinda pissed in a way..I coulda saved 30 bucks on even a 300W psu! wtf??!

Big deal. Does it work fine? I remember one time I got a PSU, and it had put this yate loon D12SH in it. Another two times, they decided to stick a 9cm fan at the bottom of it. One of those times, they used these noisy YS tech fans in them, 3000 and 2500 rpm ones.

But, yeah, everyone seems to grossly overestimate power supply requirements. I think the current "in thing" is to get power supplies that would pull more power than the wall socket can provide if at full capacity.

One word of caution: the Kill-A-Watt and similar don't really do instantaneous load. Digital things like CPU and GPU are really good at having millisecond power spikes that aren't caught by such a device. This is one of the reasons CPU draw is almost always so much lower than TDP. Those C2D really do sometimes draw something like 65W, just only for a millisecond or so and then it's back down to half that or less -- even at full utilization.

So, that said, it is quite possible that the instantaneous draw of your PC might get up to 300 or even 350W. But does it really matter? After all, PSU are usually rated for an instantaneous load of 110% of their continuous rating. So, even a 300W PSU could probably live with a system that wanted 350W for a millisecond at a time, here and there.

AFAIC, a good rule of thumb is that if you have only 1 video card and no more than 4 HDD, you don't need more than a 400W PSU. No matter what components you have, I think you would have to work very hard to come up with a combination that needed more than 600W. Still, I don't mind that vendors are selling lots of 750W+ units. That's more profit for them to develop newer and better technology that can trickle down to the units I'd actually buy. Big Picture-wise, it would be terrible if those big units had poor efficiency, but happily by and large they have excellent efficiency, so the suckers aren't even wasting much electricity.

Welcome to the SPCR Army Of Power Supply Truth. Now when you see people recommending stupidly over-specced PSUs for modest PCs on other forums, it is your duty to point out that they are perhaps not as correct as they need to be if they're going to be giving out advice. Stop people wasting other peoples money!

yeah! i didn't think of that..you're probably right, becasue I noticed it can go from "gaming" wattage to "idle" wattage in under a second..so I could see it having a quick power spike that the killawatt doesn't see between screen refreshes.

Another thing i didn't anticipate was the power draw in standby mode. 5 nights out of the week I standby my system to save power..one night i leave it on for maintenance, and the other night I shut down. In standby, the computer draws about 85W! isn't it supposed to be a "low power state"? It kinda made me reconsider shutting down on a daily basis.



Thanks nutball (that sounds weird..haha). Between the forums and the actual reviews on this site..I have learned so much and I cant wait till next summer when I build my next comp. maybe ill even use my 520 thats in there now..sinse its so overkill for my current rig, and buy a 400W psu to replace it...

There are various levels of "standby / sleep". See for example this article. It sounds like your PC may be using S1 rather than say S3 or S4. Try checking your BIOS to see what's configured there. Typically I see power consumption from the wall of <10W for my PCs when they're in S3(STR) even though one of them idles at >100W.

wow..theres something I never knew..thanks for enlightening me. If it is in s1, that would be weird..it seems s1 is an older thing. Either way, I will check.

It just didn't make sense to me that it was 85W cause the hdds are both off, suposedly only the memory is being powered, and the only fans that it has on during standby are the front and back case fan..which could only draw 6-7W max and probably not even cause they are undervolted.

I will check that when I get home.

Hi,

The actual DC power that the PSU is supplying (and how it is rated) is 15-25% LESS than the AC reading on the Kill-A-Watt meter! So your 230watt reading means that the DC use of the system is probably more like 172-195watts!

This is exactly why when we get a question from someone wanting advice on a 500-1000watt PSU, you will see the response "you will not need anywhere near that much power...". Not to toot our own horn, but we know a thing or two here at SPCR!

I think the instantaneous readings on the Kill-A-Watt are probably pretty accurate, BTW. Any use that is more transient than it can react to won't matter -- any decent PSU can handle that to well above its rated continuous output...

Those of us who have been hanging around SPCR for quite a while know that power consumption is very overrated or overestimated. We all want to be on the side of caution, understandably. But most of these high wattage PSUs are much more than a typical contemporary system needs. Manufacturers, review sites, PC magazines have spread a lot of fear in recent times about the need to get a high powered (500-1000W+!) PSU for a current system because they assume people should have the option-if-ever-needed of running multiple graphics cards for high powered gaming. Of course, not everyone needs or wants a computer for this purpose and it's not a one-size-fits-all market.

What I do get annoyed with however is people constantly recommending these mysterious got-to-have legendary 300W PSUs that must be the source of all greatness. Unless they are talking about the rubbish OEM PSUs that get bundled with corner store PCs, are there any high quality ones still available -- and outside N.A. and E.U. zones? No, I don't think there are.

The lowest rated brandname PSUs I can find in retail channels (in my locality) are Antec Earthwatts 380 (only when bundled with NSK case), Earthwatts 430, Seasonic S12II-430 and Corsair V/HX450. I still cannot find one of these legendary 300W PSUs.

With all the focus and development on higher wattage units, I don't think I will find a high quality ~300W PSU soon. It's a shame, as any system I build or will consider building will not go over 100W .

That's where the PicoPSU comes to the rescue!

nutball is certainly correct. The only way standby could be this high is in S1 (which basically only turns off the HDD). Also, fans still running are a sure sign of S1. In S3, only RAM remains powered and all fans are off. The first thing to check is your BIOS. Often you have to enable S3 support there. Also, if you are using Windows XP and you have Wake on USB enabled, there is a Registry setting you may have to change to keep it working with S3 (google this issue for complete information). Also, I find on some motherboards Wake on USB and S3 just aren't compatible, due to incorrectly provisioned 5V standby circuit. On my Asrock MB, I find I can have either working S3 or working Wake on USB, but not both (this is despite having the specified jumper in the setting to enable their coexistence).

Yes, PicoPSU should be my best friend but at ~AUD$180 (Pico+power brick+shipping) it is almost my worst enemy . My Corsair PSU costs half that. It would take years to recoup the costs from the Pico's efficiency.
The heart says "Silence at any cost"; the head says "But not at that price".

CONFIRMED. my computer was going into s1 standby..which is basically a tiny bit lower power consumption than idling. Useless imo.

I set my bios to only do s3 suspending, and it now draws like 2 watts ..as opposed to 85. THANKS so much for you're post. u prolly just saved me a bunch of money over the life of this thing lol

There's nothing wrong with buying a 500W quiet PSU if that's the only option, you're aware you're being stiffed paying for watts you'll never need, and so on.

What bothers me is this.

I have one for you. I was unemployed for a few months and was at home all day looking for work on my old, very inefficient computer. Eventually I found a t job and got back to work. What I found was that by turning the computer while I was at work, I reduced my power bill by 60% (at the least). I now only pay $10/month for all my hydro consumption.

I guess the moral is: We can save a lot of money and energy by turning off our computers as well as getting LCD monitors and power supplies rated for our needs.

I guess what's sad is back then you were arguing against people who claimed you should never go below 350W PSU. Now those same people would be advocating 750W as the standard! Meanwhile, typical PC power consumption is, if anything, less than it was in 2006.

$84 for picoPSU 150XT
$49 for 80W brick / $69 for 100W brick

Can't guess shipping costs but they are even Perth-based. I suppose with shipping it's possibly close to $180 though...

I bought an Seasonic S12-330 about two years ago and haven't regretted it since. It's been powering my HTPC (first an AthlonXP with Geforce 6600GT, then an X2 4850e/780G combo) for quite some time and hasn't complained once.

I'm sure you can't get them anymore though. However, there is the 400W FSP Source PSU (80 Plus).

The S12 II 330W PSU is still available (I had that as a possibility in one of my recent Newegg lists). Though Seasonic's site only lists S12 II Bronze, so they may be getting another update (since the ones on Newegg are only 80Plus, not Bronze).

Hi,

Here's a $50 85% efficient 400watt PSU from Fortron Source:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817104052

Okay, thanks for that. Wasn't aware of that vendor. I was going off Vastute's pricing. Even so, 84 + 69 + 20 (my estimate shipping to Perth, to be on safe side) = 173. Still quite pricey for me, but not totally off the scale. Otherwise, the Pico is almost perfect for the majority of my uses.

pico ... what a fun word to say.

Seasonic S12/II-330-380 were never available in Australia, as far as I'm aware. I can find a FSP 350W for ~$50, but it's not even listed on FSP's website. It doesn't look to be 80+ either. So I'm guessing that model is OEM type fare. Corsair has CX400 which I forgot to mention. It's around $80 here. That appears to be about the nearest match I can find to a 300W high quality PSU, that's also 80+ certified and has the benefit of Corsair's backing. But I already have a VX450, the best I could find at the time.

pico-BOO!

Im thinking the next big thing will be power supplies with two ac plugs that must be plugged into separate 15 amp breaker circuits. or maybe just a 220v PSU?



Picabo ICU

Wonder how many people hung up the phone thinking they called the kindergarten instead of the hospital.

No worries. Didn't know of Vastute myself, so thanks for the link. I spotted a 150W brick there which I haven't seen before. Wonder if it has an active fan in there somewhere ... (the 100W brick from mini-box.com.au has, apparently).

actually, i've been struggling with the same problem for a little while now, and came across something interesting: there's a bloke on eBay [Oz] selling Ipex branded SeaSonic 300W SFX PSUs for $30 shipped [quick ebay search - aelcomputers is the guy you're looking for.

i've bought 3 from him now, and i have to say they are superb. they make so little noise, i have a hard time telling when my PCs are on =) now obviously, they're SFX and so they won't fit normally in ATX cases without a bracket being made or bought, but that's not beyond anyone i've ever met.

currently, my main PC is running an X3 720, 4gb ram, WD 640gb hdd, pioneer dvd drive and 7900GS [9800GTX wouldn't fit in case...=(] [which reminds me, i need to post those pics =)] and it hasn't missed a beat with the 300W supply. will be grabbing a 4890 when my tax return comes through, and have no doubts it'll handle even that fine =)

so yeh, a quick reply turned into a logner one, but just wanted to let my fellow Aussies in on the scoop =) now, don't go buying them all so that i can't get any more!! =P

Shobai, you don't happen to be that vendor, do you? You're certainly giving it a good plug? J/K

$30 shipped is a good bargain. Haven't seen an Ipex product for years. I already have a good working PSU and don't need another for now. But thanks for letting us in on the deal. I'm sure many people in Oz will appreciate that as 300W Seasonic quality PSUs are pretty much extinct in most PC retailers.

Given the newest seasonic gold-rated 650W PSUs can still achieve 88% efficiency when only delivering 62.4W DC and can stay in fanless mode up to around 300W, I don't think you need to worry so much about getting a low wattage PSU to maintain efficiency anymore.

They are $26 more than the pico psu + 100W brick mentioned below and you have an extra 550W if you happen to need them.