Underpowered PSU...Will it Hurt Anything?

[The-Noid]

Too much load for that 350w PSU. This is plain and simple.

12v rail is rated at 18a that is spec. There arn't multiple rails. HP Service Manual FTW.

Rest goes elsewhere. That is 216w. Not enough to power that fancy smancy cpu, and fancy smancy video card.

You can get a 500w PSU for $35, what are we even arguing about? If you don't have $35 you should find a new hobby.

Done and Done.

 

[postmortemIA]

Originally posted by: Yoxxy
Too much load for that 350w PSU. This is plain and simple.

12v rail is rated at 18a that is spec. There arn't multiple rails. HP Service Manual FTW.

Rest goes elsewhere. That is 216w. Not enough to power that fancy smancy cpu, and fancy smancy video card.

You can get a 500w PSU for $35, what are we even arguing about? If you don't have $35 you should find a new hobby.

Done and Done.

You can't get good 500W PSU for $35, you can get PSU with label "500W"... chances are that HP unit is better quality than such PSU

Give it try.

 

[JEDIYoda]

Originally posted by: postmortemIA

Originally posted by: Yoxxy
Too much load for that 350w PSU. This is plain and simple.

12v rail is rated at 18a that is spec. There arn't multiple rails. HP Service Manual FTW.

Rest goes elsewhere. That is 216w. Not enough to power that fancy smancy cpu, and fancy smancy video card.

You can get a 500w PSU for $35, what are we even arguing about? If you don't have $35 you should find a new hobby.

Done and Done.

You can't get good 500W PSU for $35, you can get PSU with label "500W"... chances are that HP unit is better quality than such PSU

Give it try.

well said!!!

For $35 dollars you get what you pay for!
$35 is cheap for a PSU thus you get a cheaply made PSU!!

 

[Yellowbeard]

$50 might be a bit more realistic.

http://enthusiast.hardocp.com/...wxLCxoZW50aHVzaWFzdA==

 

[tomoyo]

Originally posted by: Yoxxy
Too much load for that 350w PSU. This is plain and simple.

12v rail is rated at 18a that is spec. There arn't multiple rails. HP Service Manual FTW.

Rest goes elsewhere. That is 216w. Not enough to power that fancy smancy cpu, and fancy smancy video card.

You can get a 500w PSU for $35, what are we even arguing about? If you don't have $35 you should find a new hobby.

Done and Done.

The amount of misinformation here is amazing. First there's a lot of newer hp psu's have definitely have more than 18a and are also 80plus.
Second, his psu is unlikely to even use more than 216W at load without adding more parts. mine does not even use over 216W...and it's far more high powered than his specs.
Third, you do NOT want a $35 psu..unless it's a frys rebate special antec earthwatts. All regularly priced $35 psus are junk unless they are rated 300W...cough fsp
Fourth, I place good odds that his system will work just fine.

 

[saiga6360]

Originally posted by: tornadobox
...the PSU has 3 +12v rails, but each of the rails is less than 22amps (but together they add up to 32amps)...

Just curious, where did you get this info about the PSU? I just got this same machine and I am thinking of replacing the PSU so I can swap in a more power hungry card like a 7950GT or maybe the 7900GS at the least.

BTW, mine came with a LiteOn 300W PSU. I definitely need to swap but looking at the PSU and the slot it is in, there is little headroom (3 1/2 inches) so do I have to settle for a mATX PSU? I've never replaced a PSU before so I need help choosing the best possible one for such a small machine.

 

[dclive]

You should be fine with the LiteOn 300W PSU and the 79xx series. I had a LO300W PSU with 4x500G, 4x1G RAM, dual-tuner, and 8800GTS/320 - with Quad Core 6600 (Q6600).

Don't believe the silly hype about 'needing' huge (over 300-350W) PSUs.

 

[saiga6360]

Thanks! That is impressive for a 300W PSU. However, I already decided to go for a Corsair 520HX for 99$ at Buy.com. If it turns out I do not need it, I can use it to build another machine to complement a X1900 XTX I have lying around.


Just for the heck of it, I tried to fit in the monstrous X1900 XTX and it is a very tight fit. Too bad I couldn't even try it because I don't have a spare PCI-E power connector.

I haven't been keeping up with the GPU stuff so I just found out there are new cards coming out in a few days. I'm interested in the HD 2950 Pro from AMD, it should be a good fit. Does anyone have the dimensions of this card? Anything over 9 inches in length is no good for this mobo.

 

[Bosconian]

Originally posted by: SparkyJJO

AC ripple didn't kill the PSU, the PSU caused the ripple that killed the card And considering the card was fine when he first got it, then the card died around the time his PSU started going out of spec it seems to make logical sense that yes the PSU killed the card.

QFT.

I love when people defend PSU's "known" for out of spec ripple with the argument of "I've never had a problem with the PSU." Umm... A PSU with out of spec ripple is going to exhibit no ill side effects. Voltage regulation, thermals, etc. may all still be in perfect check. It's the excess regulation having to be done by other components that's going to suffer.

Sucks, but we've dug our own grave when it comes to computer component quality. PSU's: we look at wattage, but not voltage distribution, regulation and minimal ripple and noise. Flipside: Graphics cards. If the bench marks look good, who cares? Never mind the card was designed for three phase power regulation when it was in the engineering stage, it has two now. Could it be that Nvidia was using a PSU with < 1% p-p of R&N? Does that guarantee that the end user will as well? End result: dead video card or, at the very least, lot's of frustrating lock ups, artifacts, etc.

 

[Yellowbeard]

Originally posted by: Bosconian

Originally posted by: SparkyJJO

AC ripple didn't kill the PSU, the PSU caused the ripple that killed the card And considering the card was fine when he first got it, then the card died around the time his PSU started going out of spec it seems to make logical sense that yes the PSU killed the card.

QFT.

I love when people defend PSU's "known" for out of spec ripple with the argument of "I've never had a problem with the PSU." Umm... A PSU with out of spec ripple is going to exhibit no ill side effects. Voltage regulation, thermals, etc. may all still be in perfect check. It's the excess regulation having to be done by other components that's going to suffer.

Sucks, but we've dug our own grave when it comes to computer component quality. PSU's: we look at wattage, but not voltage distribution, regulation and minimal ripple and noise. Flipside: Graphics cards. If the bench marks look good, who cares? Never mind the card was designed for three phase power regulation when it was in the engineering stage, it has two now. Could it be that Nvidia was using a PSU with < 1% p-p of R&N? Does that guarantee that the end user will as well? End result: dead video card or, at the very least, lot's of frustrating lock ups, artifacts, etc.

All good points. And, the bad thing is, it may take a year for the damage to accrue to the point that the card fails. But, by then it is too late. And, you can rest assured that there WILL be some damage to other components in the same time it took the weak link of the chain to die. Bad PSUs WILL kill your entire system over time given enough time. I have seen it before.

 

[JEDIYoda]

Originally posted by: dclive
You should be fine with the LiteOn 300W PSU and the 79xx series. I had a LO300W PSU with 4x500G, 4x1G RAM, dual-tuner, and 8800GTS/320 - with Quad Core 6600 (Q6600).

Don't believe the silly hype about 'needing' huge (over 300-350W) PSUs.

Impressive but I highly doubt the accuracy of said above statement!
There are so many ways that stement is wrong......

First of all for how long?
Second there is noway if what you are claiming is true that you were running said PSU in it`s so to speak sweet spot!
In fact you were probably over exerting your PSU.....

Then again how many amps on the 12volt rail/rails?--link please..

There is noways the build quality or the efficiency was even close to newer 500watts PSU`s even.

There is a hige difference between being fine and 6 months to a year from now having to replace hardware or even the PSU becuase "oh you should be fine".
Define the word FINE?

I would agree he doesn`t need a PC Power & Cooling 850 or a UltaX 1000.....
But at the same time a little descretion is needed.
Doing what you suggest will make him have to upgrade his PSU anyways a lot sooner than later!

He should not have to upgrade (when he builds a different computer or adds more fans or hardware) to a new PSU if he bius a quality PSU this time around!

It`s about time you let the - you do not need that much power dog go to sleep! It`s highly inaccurate and misleading!

Peace!!

 

[AmberClad]

Agree w/ JEDIYoda.

I've had shoddy PSUs that should have had more than enough wattage to handle a system, in my case a 450W PSU to power a 2004 system (P4 + GeForce 6800). The setup was fine for a few months, but started to have stability problems after a while. At first, it was the odd restart, but gradually advanced to the point where it'd take several power cyclings to even get the thing to boot. I switched out the PSU at that point because of the horror stories where people waited too long after the warning signs, and had the PSU blow on them, taking motherboards and other parts out along with it.

Point being, fine now doesn't mean fine months down the road. I opened up the PSU to do an autopsy on it, and sure enough -- bulging capacitors.

 

[dclive]

Originally posted by: JEDIYoda

Originally posted by: dclive
You should be fine with the LiteOn 300W PSU and the 79xx series. I had a LO300W PSU with 4x500G, 4x1G RAM, dual-tuner, and 8800GTS/320 - with Quad Core 6600 (Q6600).

Don't believe the silly hype about 'needing' huge (over 300-350W) PSUs.

Impressive but I highly doubt the accuracy of said above statement!
There are so many ways that stement is wrong......

First of all for how long?
Second there is noway if what you are claiming is true that you were running said PSU in it`s so to speak sweet spot!
In fact you were probably over exerting your PSU.....

It's entirely accurate. That is what I was running. I then had to get a seperate media center going, so I broke up the setup into 2 PCs and that changed things a bit.

Sorry if I don't buy into the 'everyone needs to massively over-spec their PSU'. I ran the PSU within spec - the Kill-A-Watt gizmo read around 250W or so, typically, under load; read a few prior threads for exact numbers, as I posted all of those #s too.

"Over-exerting your PSU"? C'mon - it's a 300W PSU, and I ran it under 300W. Case closed. Do you worry about over-exerting your CPU when you run it at 100% for a few days? Do you overclock your CPU? Why are people OK with OC'ing a CPU, but not OK with running a PSU within spec?

Anecdotal stories about bulging caps and people's beliefs in why that happened are interesting, but the fact remains that todays systems take LESS power than the P4/3.4 systems from 2 years ago, and Anandtech's own reviews say 200W-250W is a typical under-load wattage usage for today's systems with single GPUs.

 

[JEDIYoda]

Originally posted by: dclive

Originally posted by: JEDIYoda

Originally posted by: dclive
You should be fine with the LiteOn 300W PSU and the 79xx series. I had a LO300W PSU with 4x500G, 4x1G RAM, dual-tuner, and 8800GTS/320 - with Quad Core 6600 (Q6600).

Don't believe the silly hype about 'needing' huge (over 300-350W) PSUs.

Impressive but I highly doubt the accuracy of said above statement!
There are so many ways that stement is wrong......

First of all for how long?
Second there is noway if what you are claiming is true that you were running said PSU in it`s so to speak sweet spot!
In fact you were probably over exerting your PSU.....

It's entirely accurate. That is what I was running. I then had to get a seperate media center going, so I broke up the setup into 2 PCs and that changed things a bit.

Sorry if I don't buy into the 'everyone needs to massively over-spec their PSU'. I ran the PSU within spec - the Kill-A-Watt gizmo read around 250W or so, typically, under load; read a few prior threads for exact numbers, as I posted all of those #s too.

"Over-exerting your PSU"? C'mon - it's a 300W PSU, and I ran it under 300W. Case closed. Do you worry about over-exerting your CPU when you run it at 100% for a few days? Do you overclock your CPU? Why are people OK with OC'ing a CPU, but not OK with running a PSU within spec?

Anecdotal stories about bulging caps and people's beliefs in why that happened are interesting, but the fact remains that todays systems take LESS power than the P4/3.4 systems from 2 years ago, and Anandtech's own reviews say 200W-250W is a typical under-load wattage usage for today's systems with single GPUs.

links please...or is your opinion just anecdotal?
Who said anything about massively over specing?
had you said a 500watt would be plenty then your credibility would not come into question.
So if i may...what wer the specs on supposed 300watt PSU?

lol

 

[dclive]

Please take a few minutes to search this same forum. '4x500' and q6600 should get a few results. We've discussed this quite a bit. You can also look on AT's reviews for their power consumption charts...all of which back up all of what I'm saying.

 

[AmberClad]

Originally posted by: dclive
Sorry if I don't buy into the 'everyone needs to massively over-spec their PSU'. I ran the PSU within spec - the Kill-A-Watt gizmo read around 250W or so, typically, under load; read a few prior threads for exact numbers, as I posted all of those #s too.

If you want to ignore the fact that it's been proven by PSU reviewers as well as user experience that many of the lower quality PSUs heavily inflate their true wattage, and that PSUs operate at a lower efficiency level when they're on the edge of their capability, then that's your prerogative.

But I wouldn't go around recommending that people go buy up CompUSA/Acer Aspire PSUs (or whatever system that PSU of yours came with) to power their high end parts. Many of us are DIYers and don't have the luxury of a prebuilt-system warranty in the event of a major failure.

 

[Lunyone]

Just thought I'd add a link that might help to spread some light on this subject just a bit.
8800gtx on 380w PSU!
http://www.overclockers.com/articles1452/

PSU - $49 shipped - $39 w/Goggle checkout Can power 8800gtx and an OC?d e6600! See link above for proof!
Antec Earthwatt 380W P/Satx 12V v.2.2 80MM P/S2 Fan 80-Plus Certified - EA380
http://www.buy.com/prod/antec-...loc/101/203477214.html

I would probably get this PSU, since it has more head room and after MIR's is cheaper than anything mentioned so far!
PSU - $60 shipped - $30 MIR = $30!! Hard to beat at this price w/30A on 12V rails combined!!
Antec earthwatts EA430 ATX12V v2.0 430W Power Supply 100 - 240 V UL, CUL, FCC, TUV, CE, CB, C-tick, CCC ? Retail
http://www.newegg.com/Product/...x?Item=N82E16817371006

Specs below:
OUTPUT SPECIFICATIONS: Antec Earth Watts 430
AC Input 100-240V ~7A; 50/60 Hz
DC Output +3.3V +5V +12V1 +12V2 -12V +5VSB
Maximum Output Current 20A 20A 17A 17A 0.8A 2.5A
Minimum Output Current 0.3A 0.5A 1A 1A 0A 0A
Maximum Combined [------130W-------] [-------360W-------] [--9.6W--] [--12.5W--]
Total [----------------------------430W-----------------------------------------]
Sorry that didn't come out well, but bottom line is 360w on 12v rails = 30 Amps total for 12v rails.

 

[Bosconian]

Originally posted by: Yellowbeard
And, the bad thing is, it may take a year for the damage to accrue to the point that the card fails. But, by then it is too late.

A year if you're lucky. Might take longer. And by then, the user is just like, "Hmm... wonder why that happened? Oh well... Let's try this again" completely oblivious to the actual cause of their problems.

 

[SerpentRoyal]

Hardware vendors are suppose to test their parts under the worst-case conditions established in the ATX power supply design guide. The better vendors will also backup their products with 3, 5, or lifetime warranty. I only measure non-DC ripples to exercise my ancient HP scope. Have never lost any component due to a bad PSU.

If controlling excessive AC ripples is a very important issue, then you would see this number reflected in the latest ATX specs.

 

[Bosconian]

Originally posted by: SerpentRoyal
Hardware vendors are suppose to test their parts under the worst-case conditions established in the ATX power supply design guide. The better vendors will also backup their products with 3, 5, or lifetime warranty. I only measure non-DC ripples to exercise my ancient HP scope. Have never lost any component due to a bad PSU.

If controlling excessive AC ripples is a very important issue, then you would see this number reflected in the latest ATX specs.

Incorrect.

There is no mandatory testing temperature in the ATX12V spec. Even if there was and it was higher than 25C, that would mean more than half of the PSU's on the market aren't following spec because more than half of the PSU's on the market are tested at 25C.

And some PSU's don't follow the ATX specs for ripple and noise yet call themselves ATX12V power supplies. Take FSP for example. They willingly publish their ripple and noise as out of spec as per the ATX12V specification, yet it's still an ATX12V power supply.

 

[JEDIYoda]

The issue really isn`t how much is too much.....
The issue really is where are all the lower wattage PSU with the massive 12volt rails?
I am not talking about the 500watts PSU.
I am talking the 250 and 300 and 350 watt PSU`s.

That article in and of itself is all well and good.
Yet-- Here is a comment`s from a different forum on this very subject -- mainly centered on dclves comments --

You should be fine with the LiteOn 300W PSU and the 79xx series. I had a LO300W PSU with 4x500G, 4x1G RAM, dual-tuner, and 8800GTS/320 - with Quad Core 6600 (Q6600). Don't believe the silly hype about 'needing' huge (over 300-350W) PSUs.

We have comments from people who actuallt test PSU`s on the above statement says--
Hmm...

The Lite-On PSU's are generally pretty good. One 79xx, I can see it. But I'd have to question the validity of the claim of running an 8800. Note the poster said "had." For how long? Had for one month before upgrading it? If it was "had for a year" I'd scream "shens."

Unfortunately it takes either a complete failure or an impossible to troubleshoot stability issue to clue some people into why you shouldn't skimp on a PSU.
***************

Every time I see somebody recommending a 100W PSU for an 8800 based system I laugh and move on.
*************

As I see it you can`t argue with these people who actually believe
a 350 watts PSU will get you though........
Yet if they were recommending the lowest model corsair or even the lower wattage Antecs I a actually honestly see no isuses recommending a lower powered PSU.

You can get a 430 ir even a 500 watt-- Neopower or the Earthwatts..etc

Yet-- If you can run dual video cards why does it appear that won`t NVidia certify for SLI any PSU`s under 500watts?


Also speaking about what manufactureres are supposedly suppose to do...thats a huge crock......
They can`t test their equipment under concievable PSU catastrophie....

also somebody states--

If controlling excessive AC ripples is a very important issue, then you would see this number reflected in the latest ATX specs.

You are trying to down play the ripple issue which is just wrong!

The ripple issue is one of those issues that as you get closer to running your PSU at max output (if thats possible.......)you have a very distinct possibility over time of losing your PSU as well as components .

Ripple issues appear to occur when 85% load or higher is reached.

Here is a good definition of ripple--
http://www.answers.com/topic/r...ltage-1?cat=technology
Ripple voltage
The time-varying part of a voltage that is ideally time-invariant. Most electronic systems require a direct-current voltage for at least part of their operation. An ideal direct-current voltage is available from a battery, but batteries are impractical for many applications. To obtain a direct-current voltage from the alternating-current power mains requires using some type of power supply.

A typical linear power supply system configuration (see illustration) consists of a transformer to change the voltage at the mains to the desired level, a rectifier to convert the alternating-current input voltage v1 to a pulsating direct-current voltage v2, followed by a low-pass filter. The output voltage vout of the filter consists of a large direct-current voltage with a superimposed alternating-current voltage. This remaining superimposed alternating-current voltage is called the ripple voltage.

Practical linear power supplies often include a voltage regulator between the low-pass filter and the load. The voltage regulator is usually an electronic circuit that is specifically designed to provide a very stable dc output voltage even if large variations occur in the input. Nonlinear power supplies, which are often termed switching power supplies or switched-mode power supplies, are becoming increasingly popular as a practical
alternative for producing a low-ripple dc output.


You cannot ignore ripple over the long term....over the short term almost anything can be ignored including buying a crappy PSU!
But in time it will come back to bite you!!

 

[SerpentRoyal]

Quality hardware vendors use the ATX specs as the general design footprint. Can anyone confirm the actual performance of any PSU without testing? NO! Again, if ripple noise is a dominant failure mode, then it would receive much more attention by the marketing departments. LESS THAN 10mV OF AC RIPPLE would be prominently placed at the top of the box.

As for the noobs harping about exessing ripples, let's post some scientific tests showing the relationship between amount of ripples vs. useful life of GPU, HDD, etc. Don't have them? Then you're still blowing smoke.

 

[Yellowbeard]

Originally posted by: SerpentRoyal
As for the noobs harping about exessing ripples, let's post some scientific tests showing the relationship between amount of ripples vs. useful life of GPU, HDD, etc. Don't have them? Then you're still blowing smoke.

Let's put it this way. No individual that I know of is going to invest time and money in setting up a system and letting it run for 24 hours a day until something dies due to a junk PSU. Manufacturers may do that but, they are not publishing their reports for others to read. So, there are not likely any publicly accessible test results showing exactly how much ripple will do what type of damage over any given amount of time to a specific type of component. However, this does not mean that it is not a factor and it is not smoke. You also don't have scientific tests showing the opposite so your point is equally unsupported and must be anecdotal or empirical.

The opinions in this thread are VERY clear. I personally am not trying to change any of them as it seems to be degrading into an argument of semantics. Cheap PSUs still suck. Underpowered PSUs have their risks. It's that simple.

 

[saiga6360]

I find it alarming that the rated wattage of PSUs have grown so much and yet there is still a lot of confusion and conflicting reports relying on individual experiences. All I can say to this is that with the money I spent for the Corsair HX520W, it better last me at least 3 years with these specs:

Q6600 @ 2.4 Ghz
2x1 GB DD2 800 mhz
1 250 GB SATA2 drive
1 PCI-E graphics card (will attempt a leftover X1900 XTX, but will buy an HD 2950 Pro or 8800 GTS later to upgrade)
1 500 GB HP Personal Media drive
1 SB Xi-Fi XtremeGamer


If I go by http://www.extreme.outervision.com/psucalculator.jsp , it comes to about 410W so I should be fine if it can be trusted. Then again, that's the problem isn't it. The PSU should be ok if I go by word of mouth, manufacturer reputation and of course, the price.

 

[SerpentRoyal]

Originally posted by: Yellowbeard

Originally posted by: SerpentRoyal
As for the noobs harping about exessing ripples, let's post some scientific tests showing the relationship between amount of ripples vs. useful life of GPU, HDD, etc. Don't have them? Then you're still blowing smoke.

Let's put it this way. No individual that I know of is going to invest time and money in setting up a system and letting it run for 24 hours a day until something dies due to a junk PSU. Manufacturers may do that but, they are not publishing their reports for others to read. So, there are not likely any publicly accessible test results showing exactly how much ripple will do what type of damage over any given amount of time to a specific type of component. However, this does not mean that it is not a factor and it is not smoke. You also don't have scientific tests showing the opposite so your point is equally unsupported and must be anecdotal or empirical.

The opinions in this thread are VERY clear. I personally am not trying to change any of them as it seems to be degrading into an argument of semantics. Cheap PSUs still suck. Underpowered PSUs have their risks. It's that simple.

My point is the reduction in mean life expectancy is small due to higher AC ripple. If there is a significant gain to be had with lower AC ripple, then you can be sure that the PSU vendors would use AC ripple as a key selling point. As of today, I don't know of a single PSU vendor with a guaranteed max AC ripple on the 3.3V, 5V, and +12V rails.

It's easy to sell snake oil to noobs.