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Proof that small psus do work :)

tomoyo

Senior member
Oct 5, 2005
418
0
0
I just built a HTPC with an Antec ISK300-65 using a standard Core I3-2100, Asrock H67M-ITX/HT, 4GB DDR3, and 2.5" hdd. Not hitting over 65W from the wall even with 4 prime95 threads and furmark 1.9.1 going at the same time. And it's 22w at idle from the wall. I'd estimate that means it's using 56-58w at most from the 65w adapter. It's silly how people keep getting 600-1000w psus for stuff that only needs 200-300w at most :p
 

superccs

Senior member
Dec 29, 2004
999
0
0
Yeah those dumbies with their real CPUs (1-4x), GPUs, and HDDs using 600-1000W psus :/
 

OCNewbie

Diamond Member
Jul 18, 2000
7,596
25
81
I don't see how that's proof of anything. You're using the slowest (I think) version of a really efficient CPU, an on-die GPU, and an SSD and you're surprised it's not using much power?

While I will agree that many people go overboard with estimating the power requirements of their rig, I don't think your setup is a good example to back up that idea.
 
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deltree86

Member
Jun 2, 2011
34
0
0
Adding a graphic card wont do much of a difference either...at most a stock dell psu in the 300-400 watt range would also do!
 

tomoyo

Senior member
Oct 5, 2005
418
0
0
I don't see how that's proof of anything. You're using the slowest (I think) version of a really efficient CPU, an on-die GPU, and an SSD and you're surprised it's not using much power?

While I will agree that many people go overboard with estimating the power requirements of their rig, I don't think your setup is a good example to back up that idea.

I'm not surprised at all. It was planned after all. Also I'm not using SSD as of yet, it's a 2.5" HDD. And the slowest versions are the pentium and/or celeron sandy bridges.
All I'm saying is that given the efficiency of a number of components out there, people definitely go massively overboard on their psus.
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
Wattage tells little on pc power supplies. Some systems use 5V more than 12V , especially the micro or mini itx systems. One system may work fine with two different supplies 1st is 700W and the 2nd 350W all depending on how the rails are used.
Anytime I build a system I add up the current requirements for each voltage and buy based on that, not the PSU wattage.
 

tomoyo

Senior member
Oct 5, 2005
418
0
0
I don't know of any legit modern pc that isn't mostly 12v. 5v and 3.3v are now rarely used in comparison. Mobos, cpus, and video cards are all mostly powered by 12v.
 

BrianTho2010

Member
Jul 27, 2011
69
0
0
I agree that most people over-purchase with their power supplies, but my system with a 4.5Ghz 2500k and HD4850 with 3 hard drives and 3 system fans is going to require considerably more than 100 watts at maximum load.

That said I am one of the few who went with a lower spec PSU at 520 watts. I would venture a guess that the lowest I could go without hitting over 90% of the rated power would be 400 watts.

Edit: eXtreme PSU calculator estimates that I need a minimum of 346 watts and 396 is recommended. So I could go with the Seasonic-X 400 watt fanless PSU if I wanted.
 
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Meghan54

Lifer
Oct 18, 2009
11,684
5,228
136
Build a low power system and don't be dumbfounded when it doesn't draw a lot of power from the wall.

Build a higher power system, such as an i7 920 OC'd to 4GHz on 1.28V, 3 HDD's, a 4870 gpu, 10 fans, two DDC2 pumps (watercooling), and you can easily pull over 600W from the wall at full tilt running.

Still cannot fathom why the OP is astounded at the predictable results found.
 

jjmIII

Diamond Member
Mar 13, 2001
8,399
1
81
I agree that most people over-purchase with their power supplies...

I'm one of those people :).
PSU's are like HDD's. It's only a little bit more money for a bigger one.
I think I pd $99 for my Corsair 850w, and like knowing I have plenty of power.
 

OCNewbie

Diamond Member
Jul 18, 2000
7,596
25
81
I got a really good deal a few years back on my BFG 800w. There was some deal with buy.com how you could get a $40 credit? or something like that. I think I paid like $40-45 for it shipped, no rebate. Newegg was selling it for over $100 at the time IIRC.
 

Elfear

Diamond Member
May 30, 2004
7,165
824
126
My BFG 800W keeps shutting down while mining. Stalker did the same thing when I was running a pair of 6950s. Within reason, it's better to have some headroom than run things near their max. I personally like at least 20% headroom. PSU lasts longer and I don't have to buy a new one every time I upgrade components.
 

Gillbot

Lifer
Jan 11, 2001
28,830
17
81
I ran a 980x rig with a 150-200w unit. It sure wasn't happy but it was enough to run some boot tests.
 

SparkyJJO

Lifer
May 16, 2002
13,357
7
81
News flash: low power computers pull little power from wall socket.

Another news flash: high end computers pull a lot of power from wall socket.

Details at 11.
 

Gillbot

Lifer
Jan 11, 2001
28,830
17
81
lol. That 980x is quite the power hungry beast. That said X58 doesn't make matters any better either.

and 18gb of ram, and a vid card which I don't even remember which one I used but it was probably an 8800gts or something along those lines.
 

BrianTho2010

Member
Jul 27, 2011
69
0
0
and 18gb of ram, and a vid card which I don't even remember which one I used but it was probably an 8800gts or something along those lines.

I am all for excess when it comes to computers, but 18 GB. Come on now. How on earth are you going to use 18GB unless its a database server of part of a cloud computing rig.
 

Gillbot

Lifer
Jan 11, 2001
28,830
17
81
I am all for excess when it comes to computers, but 18 GB. Come on now. How on earth are you going to use 18GB unless its a database server of part of a cloud computing rig.

I do lots of specialized database work and ram gets gobbled up quickly. I'm actually going to upgrade it to 24gb or more soon.
 

mindless1

Diamond Member
Aug 11, 2001
8,754
1,760
136
It's sort of strange when people think in terms of "barely enough". I mean, do you want barely enough light in a room, barely large enough clothes, barely enough to eat? Why then would you want barely enough PSU?

If you are running a PSU nearer its rated output power you reduce its lifespan. This is something reviewers cannot do for you, run their hotbox for years at a time to let you know how long a PSU lasts at any output power.

To me and others it isn't as relevant if a "500W" PSU can output 500.000W at 40C, it's how long it will live outputting 300W. When you buy a PSU capable of higher current certain things are improved like transistor die size, heatsink thermal effectiveness (vs thermal density of transistors, diodes, etc), capacitor ESR reduction and physical size (as it relates to surface area to shed heat), fan airflow capability, etc.

In addition to longer life, having higher capacity means it covers a larger range of potential system changes or upgrades later.

Further, there's often minimal price difference between a quality 300W PSU and 500W PSU as 500W or a little higher has become a popular enthusiast wattage range quite often put on sale or with a rebate, so unless you need a mATX or smaller form factor, there is little reason not to get the higher capacity PSU except that with systems that are very low loading you might suffer a few % efficiency drop.
 

Zap

Elite Member
Oct 13, 1999
22,377
7
81
It's sort of strange when people think in terms of "barely enough". I mean, do you want barely enough light in a room, barely large enough clothes, barely enough to eat? Why then would you want barely enough PSU?

Your thought process needs some tweaking. It isn't "barely enough." It is "not too much." What if you put so much light in a room that you need sunglasses or you are blinded? Teen fashion aside, what if your clothing was so large that they just slide off your body? What if you were already completely stuffed and you were served another meal?

If you are running a PSU nearer its rated output power you reduce its lifespan.

But you won't be running it near rated output all the time, unless you do stuff like Folding. Even gaming won't stress it that much, plus all the time in-between uses less power.

Further, there's often minimal price difference between a quality 300W PSU and 500W PSU as 500W or a little higher has become a popular enthusiast wattage range quite often put on sale or with a rebate

This is absolutely true. It is the reason, for instance, why the Corsair CX400 was discontinued. It was a quality Seasonic made unit with a $70 MSRP. Between it and $100 was the 450W and 550W units. Most people just elected to pay the few bucks more.
 

mindless1

Diamond Member
Aug 11, 2001
8,754
1,760
136
^ But too much with a PSU that regulates itself? You could have "too much" if it were an unregulated design and so the voltage rose to dangerously high levels but if talking lights in your room being too bright you can regulate that by how many are turned on.

Even if your PSU is seldom near it's max rating, % load is still a factor in longevity. As I began to mention previously, too few seem to realize it because reviewers cannot practically test for this, although another possible reason is that enthusiast PC power requirements have gone up and ATX spec changed in addition to most PCs being from an OEM with a new PSU included, so lots of people have no idea if their old 300W ATX PSU would be alive today if the system were still used regularly.

I feel we have reached a different period now, there is no higher voltage rail on a PSU to switch to now, and the average consumer PC isn't likely to need the scale of wattage increase we've seen over the past dozen years, in a dozen years from now. A PSU bought today is quite possibly viable for a longer period of time, IF it doesn't fail prematurely... but what if PC power consumption does go up? The higher capacity PSU may have you covered for that too. I recall seeing a lot more posts on the internet about whether someone's PSU is "enough" for their next build, compared to whether they should buy a smaller PSU for their next build.
 
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Zap

Elite Member
Oct 13, 1999
22,377
7
81
Sure a PSU regulates itself. How about paying extra for something you don't need? What if a restaurant gives you a 32oz soda for $2, but will give you unlimited refills for $5? Most people won't drink more than 32oz (with a full meal) so sure you can buy more and not use it, but it is a waste of money.

Nobody knows about longevity related to what kind of load it runs. It is like believing in God. Some do and some don't. People that do think they are right. People that don't think they are right.

PC power consumption will not go appreciably up. Highest TDP (which may or may not relate to how much it actually draws) of CPUs have been 140W for a consumer CPU. Graphics cards typically max at 225W though a few crazy ones (Asus Matrix?) can in theory draw over 600W.