Anyone else have heat issues with the Seasonic S12 series?

[Bob_the_lost]

Ok, the fan on the s12 sucks the air up towards the top of the case, both the internal end towards the Optical drives and the external end are open to some extent.

There is hot air "venting" into the top of the case itself, while the optimum would be for the air to be vented out the back. Overpressure seems not to make any difference (i'm not surprised), blocking the optical end vents does. I'm getting the situation right here?

I think the problem is the 120mm fan forcing the air up into the PSU. The 120mm fan will produce a higher pressure inside the PSU than the average inside the case, the pressure at the Optical drive end will be lower, thus the hot, higher pressure air will migrate into the Optical drive area. (The pressure arguements are right, but unless you have a higher pressure at the optical drive end than inside the PSU hot air will go the wrong way and that ain't gonna happen without some help).

You could stick a case fan at low revs blowing air into the back of the PSU, kind of negates the point in a quiet PSU but it would work.
You could drill holes into the top of your case to allow hot air to vent there (it would be an absolute bitch on my system, as well as acoustic problems.)
You could block the vents and try and kill the PSU before the end of it's warranty period.
You could make an air duct that goes up the backs of the Optical drives and then along to the PSU, if you were to force air in at the HD end then it should help a bit.

Or you could pack the case with explosives, strap a bar mine to the PSU and find a bunker to sit in.

(edited to make sense)

[NeilBlanchard]

Hello Bob,

What are you saying -- that all 120mm fanned PS's are flawed? You still theorizing, too.

If you have an S12, with the system on: if you stick your hand a little behind the rear vents, do you feel air moving? If so, is it noticeably warm?

What are the temps of the optical drive? What if you mount it in a lower bay? Or, stick a piece if cardboard about an inch away from the vent, to deflect this alleged flow of hot air: does this change the temp of the optical drive?

[MikeC]

Actually, I think all 120mm fan PSUs ARE flawed.

The main issue is that the airflow from the fan must take a 90 degree turn in order for it to go anywhere. This always results in some backflow, which leads to ineffective airflow and turbulence, which leads to more noise. It also means some places in the PSU may never get adequate cooling -- or maybe they get no airflow at all, which is what I am saying about PSUs that have no openings whatsoever except the back panel. In comparison, an 80mm fan PSU has a straight through airflow path. It's much easier to design an airflow path that includes all the hot components that need it.

Having said all that, despite the theoretical issues, AFAIK, the S12-430 is quieter (in actual use) than any 80mm fan PSU in commercial production. The margin may be small in some cases, but it's definitely there. It has to do with the amount of air that a 120mm fan can move at a given rpm (noise level) compared to an 80mm fan, which has only half the fin area. And the decent fan and the excellent HS & fan controller in the S12.

My take on the extra vents in the S12 is that they do help ensure some airflow across all the components. In that sense, it is good engineering.

I have no doubt that this means some heat is being pushed back into the case. The main question, to me, is whether this extra heat...

1) causes other components to misbehave or wear out sooner?
2) is a big portion of the total heat passing through the PSU?

And my answers are:
1) probably not
2) no way -- the inside openings are tiny in comparison to the main exhaust vents, which cover almost the entire back panel. Which side do you think poses less resistance to airflow?

If you really are paranoid about this, there is a really simple solution:

Empty the top CD bay and replace the bay cover with a piece of ordinary open-cell foam (maybe half an inch thick) at the opening as a filter intake. The CD bay will become an intake vent if you have only exhaust fans. This will ensure that no heat is trapped between the PSU and the CD drive.

[Bob_the_lost]

Hello Bob,

What are you saying -- that all 120mm fanned PS's are flawed? You still theorizing, too.

Yes i am theorising, but i'm right (Damn i sound arrogant! )
Not sure if this is going to work (it didn't ), if not expect a few edits:

Code: Select all

_________________________________________________________
|                                                         |
:         PSU, with lots of stuff in it                   :-----------------------
:         breaks up any direct air flow                   :------Wires ----------
:                                                         :-----------------------
:                <---              ---->                  :
:                                                         :
:                           / \                           :
:                            |                            :
:                            |                            :
|_......................................................._|

The air is sucked in through the massive bird shredding industrial size yet almost silent 120mm fan, this produces an area of high pressure, the air will move from an area of high pressure to one lower. Both ends of the PSU are at a lower pressure, thus it will vent to either end. If there is nothing to stop the air flowing towards the wires end or nothing forcing more air out the back of the PSU then it's going to "backwash" your case.

If you were to angle the parts so that the air is deflected towards the rear of the PSU then you'll get most of it going out the back, if it's just a jumble of heatsinks that don't guide the air out the back you'll get it venting wherever it likes.

As to a flawed concept of course it is, this forum is all about adapting high performance, high heat parts to an old outdated design (ATX) while keeping it quiet, you remember when CPUs were passivly cooled? A second fan, at either end of the PSU would help noticably but would raise the noise of the PSU.[/code]

[MikeC]

The air is sucked in through the massive bird shredding industrial size yet almost silent 120mm fan, this produces an area of high pressure, the air will move from an area of high pressure to one lower. Both ends of the PSU are at a lower pressure, thus it will vent to either end. If there is nothing to stop the air flowing towards the wires end or nothing forcing more air out the back of the PSU then it's going to "backwash" your case.

Wrong!! The two ends do NOT represent "equal" low pressure areas. One end is almost completely open, the other end is almost completely closed. There is much less resistance on the open grill side, so far greater air flows out the back. It's simple & obvious. Only a small portion of the total air flowing out of the PSU actually comes out the small holes on the inside face.

[Bob_the_lost]

It's only wrong if you interpret it that way. Technically it's not a fully comprehensive answer that leaves too much unsaid. :p

The pressure inside the PSU, above the 120mm fan will be higher than the pressure at either end, which means air will not flow into the PSU from either end. People were making the assumption that because the pressure is higher inside the case than outside (with possitive pressure) it means that the air will flow out through the PSU. It won't, not in that direction.

It is simple and it is obvious, but that's never meant that people agree with it or even think it though.

[aristide1]

Actually, I think all 120mm fan PSUs ARE flawed.

The main issue is that the airflow from the fan must take a 90 degree turn in order for it to go anywhere. This always results in some backflow, which leads to ineffective airflow and turbulence, which leads to more noise. It also means some places in the PSU may never get adequate cooling -- or maybe they get no airflow at all, which is what I am saying about PSUs that have no openings whatsoever except the back panel. In comparison, an 80mm fan PSU has a straight through airflow path. It's much easier to design an airflow path that includes all the hot components that need it.

Having said all that, despite the theoretical issues, AFAIK, the S12-430 is quieter (in actual use) than any 80mm fan PSU in commercial production. The margin may be small in some cases, but it's definitely there. It has to do with the amount of air that a 120mm fan can move at a given rpm (noise level) compared to an 80mm fan, which has only half the fin area. And the decent fan and the excellent HS & fan controller in the S12.

My take on the extra vents in the S12 is that they do help ensure some airflow across all the components. In that sense, it is good engineering.

I have no doubt that this means some heat is being pushed back into the case. The main question, to me, is whether this extra heat...

1) causes other components to misbehave or wear out sooner?
2) is a big portion of the total heat passing through the PSU?

And my answers are:
1) probably not
2) no way -- the inside openings are tiny in comparison to the main exhaust vents, which cover almost the entire back panel. Which side do you think poses less resistance to airflow?

If you really are paranoid about this, there is a really simple solution:

Empty the top CD bay and replace the bay cover with a piece of ordinary open-cell foam (maybe half an inch thick) at the opening as a filter intake. The CD bay will become an intake vent if you have only exhaust fans. This will ensure that no heat is trapped between the PSU and the CD drive.

While I agree with this, it must be noted that the air path, 90 degrees or straight is anything but smooth. With a 90 degree bend I would think you would require and desire turbulence to cool off areas without airflow (regardless of noise) or as they did it, add more holes to keep air moving inside the thing.

Even the straight through path with the smaller fan is going to have some problem areas around the corners of the back panel, whether anything is actually there is another story.

I never have these issues with high end audio. Yeesh!

And Mike you sure were right about trying to find one of the HT series PSs. They are on Seasonic.com, but seasonicusa.com.

[Oliver]

Though I cannot prove it was not incidental, I believe my original optical drive really shook more and made greater vibartional noise when it was installed next to the s12 430.... Though the optical drive was probably defective, the vibration was tremendous when it was next to the s12 430, but it may have been incidental. That's no bull.

Actually that is bull. If optical drive was defective and vibrated, that's self-explanatory. The S12 had nothing to do with this. I've played with many a hot system and never noticed any change in CD drive noise due to heat.

1st off, I said it may be incidental.
Yes, maybe it has no effect on a properly manufactured optical drive.
But in general, if a subpar component gets hot, the heat can exacerbate its performance. So, to say what I am saying is bull, may be premature.

Now, onto the issue of heat being expelled by the s12 430w in my system out the front vents. No I did not put a thermometer there. I opened the case and put my hand there. It was very hot on the backside of the optical. And I clearly felt the heat on my hand, blowing from the vents of the s12 facing the front of the case.

I think bob-the-lost is point on.
Me, I just look at the situation as open area in honeycomb back versus open area in front vents. Of course there is turbulance, and friction of the vents shapes and internal components, and air that doesn't get out the one side being the backstop that the air that goes out the other side uses to get out the other side.

I think the big issue also is that there are those 3 big components that have copper wires coiled around them placed in front of each of the side/front vents on the s12 430w. There are 2 in front of the front vents, and 1 in front of the side vent. Now if those things are hotter than the general air flowing around the inside of the PSU, then even a smaller air flow out the front vents could theoretically be carrying an equivalent or more BTU out the front vents than the honeycomb back vents. I am not saying that is the case in the s12 430w, but what I am saying is that would explain a small area allowing a significant amount of BTU to pass through it. So it could be more than just pressure differences and calculating the area of honeycomb back vents versus front and side vents. There may be a difference in temperature of air out the one vent or the other , in addition to total quantity of air flow.

[hofffam]

I have a one month old S12-380 in my new SLK3000B.

I was so impressed by the S12 at first. I thought: "wow - it isn't blowing any air at all - the fan must be really running slow." It was VERY quiet. I paid no attention to it until I read this thread. I opened my case - what do you know - warm air leaves the PS out the vents near the optical drives. Almost no air leaves the PS through the "rear" vents. My case has one YL exhaust and one YL intake. I plan to experiment with covering some or all of the "inside" vent slots. I'm puzzled but the behavior of the Seasonic. In my S12-380 - far more PS air goes into the case than leaves it.

[jermaink]

So how would the Seasonic S12 type of PSU interract with an Antec P180 type case (where there is a isolated bottom chamber, where a fan can blow at the PSU).

[StarfishChris]

The total area of the rear vent is very large compared to the front vent. If the same amount of air comes out the rear vent you would probably have a hard time noticing it - cover up the inside vent and see if you can feel anything then.

[Bob_the_lost]

So how would the Seasonic S12 type of PSU interract with an Antec P180 type case (where there is a isolated bottom chamber, where a fan can blow at the PSU).

Well the 120mm fan would be doing absolutly nothing for a start. All the air moved would be due to the case mounted one. Which means you'll have a fan spinning for no reason.

[jermaink]

So how would the Seasonic S12 type of PSU interract with an Antec P180 type case (where there is a isolated bottom chamber, where a fan can blow at the PSU).

Well the 120mm fan would be doing absolutly nothing for a start. All the air moved would be due to the case mounted one. Which means you'll have a fan spinning for no reason.

Wouldn't it aid the cooling of the HDD? But I was really asking about the interraction of this 'heat issue' and the unique placement of the PSU chamber in the P180.

[Bob_the_lost]

This "heat issue" isn't all that much of a problem. The s12 design just doesn't seem to be well suited to the 180's seperate chamber system, you want a straight through fan rather than a fan that operates at 90 degrees.

The 120mm PSU fan will do nothing for the hard drives.

[Dish]

Tape all the ventilation holes the PSU don't cover, then the only way for the enclosed department to get air in is past the hard drives.

[hmronin]

This "heat issue" isn't all that much of a problem. The s12 design just doesn't seem to be well suited to the 180's seperate chamber system, you want a straight through fan rather than a fan that operates at 90 degrees.

The 120mm PSU fan will do nothing for the hard drives.

I disagree with this last statement. THe P180 was designed to accommodate virtually all types of PSU's, as evidenced by the raised platform it uses to suspend the PSU and thereby allow air in from the bottom. Also, the vents on the rear panel surrounding the PSU air discharge vents also indicate that the P180 design takes into consideration the use of fanless PSU's. By all accounts, the P180 remains to be one of the most versatile cases currently available for the mainstream consumer...it just depends on what type of PC you are trying to create to customize this case to suit your needs.

The S12 design, though possibly not the best, works well in the P180 specifically because of the separate lower chamber. By having the PSU heat segregated from the rest of the system components, it minimizes any performance effects to other parts (MB, CPU, GPU), while simultaneously providing air flow for the hard drives. All this has been pointed out in many reviews, including the ones on the P180 by SPCR.

The bottom line is that having the lower chamber encourages straight in/out airflow, in the sense that the PSU fan serves to provide a higher air pressure in the rear of the P180's lower chamber, relative to the air pressure on the inlet side of the P180's lower chamber. Therefore, you will have air flow across your hard drives, and the PSU(More so if you cover the rear case vent holes meant for fanless PSU's). Will some of this air enter back into the lower chamber thru the s12 vent holes? Yes. However, there's no place for this air to go but back into the PSU and eventually out of the case. At most, having the front vents in the S12 causes the average temperature in the PSU to increase slightly. None of the secondary effects discussed in this post or in others, should significantly affect performance, provided a P180 case is used.

StarfishChris also brings up an excellent point, not to mistake air velocity with air volume. Due to the huge difference in open surface area of the rear PSU vents vs. the front PSU vents in the S12, the volume of air leaving the case is much greater than the volume of getting blown back into the lower chamber. Using your fingers only help you detect the velocity of the air being moved, not the volume.

[Bob_the_lost]

Using a fanless PSU makes more sense in the P180 than a s12. It's designed for a straight through airflow, while the s12 is desinged to act as a means of evacuating heat from the CPU. It's the wrong design to get the most out of the case.

Seasonic do straight though PSUs don't they? I'd go with one of them, or personally i'd get a Phantom, if you're going to spend that much on the case you might as well go for the best option all round.

[hmronin]

Using a fanless PSU makes more sense in the P180 than a s12. It's designed for a straight through airflow, while the s12 is desinged to act as a means of evacuating heat from the CPU. It's the wrong design to get the most out of the case.

Seasonic do straight though PSUs don't they? I'd go with one of them, or personally i'd get a Phantom, if you're going to spend that much on the case you might as well go for the best option all round.

Though the P180's lower chamber is great for straight through airflow using a fanless PSU, I question whether the differences between an S12 and any given fanless PSU are measurable, performance or otherwise.

And even if they are measureable with instruments, are these improvements noticable to the user? Consider that using a fanless PSU in this location still requires the use of a fan to generate airflow, in this case, the Antec Triflow fan in the middle of the lower chamber. If you opt not to use this fan, you may still have a fan on the "fanless" PSU, like the Antec Phantom 500. So in every case, you have a fan moving air, either in the PSU, or in the lower chamber. This is the main reason why I have difficultly deciding to adopt fanless PSU's, they still require a fan to pull off warm air. The only situation I can see where its advantageous to have a fanless PSU is if you located it remotely from the computer case, but then you may run into cable length issues.

The other point I would make has to do with cost. Whatever "sense" it makes to go with a fanless PSU, it certainly doesn't make "cents". Going with a 500 watt S12 vs. the Phantom 500 will cost you a premium of 25%. I would also guess that most of us looking for silent computer would be loath to even need anything close to 500 watt capacity, so getting a smaller S12 bumps up that premium to 65%.

So unless you plan to have your PSU outside your P180, I'm not sure what you gain performance wise, or noise wise by going with a fanless PSU.

[Bob_the_lost]

I wouldn't be so sure on the money side, the phantom is 5% more efficent than the s12 @ 200W load and that only increases if you have a higher load. If you're using a high powered system then the waste heat cost starts to build up if you're one of those people who leaves thier computer on all day.

(What warranty does the s12 ship with? If it's less than the phantom's then there's another thing to count against it)

The S12's fan doesn't aid air flow at all. Which means it's a fan spinning for nothing. With the S12 you have 2 fans going, the case and the PSU ones. With a Phantom 350 or a 500 (at low loads, probably slightly better than the review as you do have airflow directly over the PSU) you only have one fan going. With the 500 you will at worst have two fans acting in serries, rather than one doing nothing but causing turbulence.

The s12 serries is a lovely conventional PSU, but it's optimised to work in a standard ATX layout, not a straight line airflow like the p180.

[jermaink]

My problem with the Phantom 500 (or 350W) is that it's performance isn't that stable when pushed. DFI Street aren't recommending Phantom 500 for systems using their Nforce 4 based motherboards. The S12 (500W or 600W) seems to be that compromise of power/stability/silence, though some people are having problems with that PSU as well (seems to be a random manufacturing issue though rather than something effecting the whole series).

[hmronin]

My problem with the Phantom 500 (or 350W) is that it's performance isn't that stable when pushed. DFI Street aren't recommending Phantom 500 for systems using their Nforce 4 based motherboards. The S12 (500W or 600W) seems to be that compromise of power/stability/silence, though some people are having problems with that PSU as well (seems to be a random manufacturing issue though rather than something effecting the whole series).

I agree too that the S12 is a compromise of power/stabilty/silence. And its a good compromise, especially if it is used in P180. With the lower chamber isolated from the CPU, MB, and VPU heat loads, the PSU fan has little work to do, other than move air for itself and any hard drives in the lower chamber. Therefore, the fan RPM (And corresponding noise) remains low, relative to what it would be if the S12 was mounted in any other case than the P180, that doesn't not offer this type of isolation.

Ths stability problems you mention also disturb me. I've read in many places about the freqency of problems with fanless PSU's breaking, even after only months of service. This may only be anecdotal evidence, but consider this: By removing an essential unit (a fan) for removing heat, the fanless PSU must rely soley on convection for heat removal. Heat is the enemy of virtually all electronic systems, so an increase in problems with fanless PSU's would not surprise me. If you add a fan to produce the air flow to remove heat from a fanless PSU, then all you've done is to turn a fanless PSU into a fanned PSU!

[hmronin]

I wouldn't be so sure on the money side, the phantom is 5% more efficent than the s12 @ 200W load and that only increases if you have a higher load. If you're using a high powered system then the waste heat cost starts to build up if you're one of those people who leaves thier computer on all day.

Granted the Antec is slightly more efficient, the difference between the two is hardly of concern. Even if you are running your machine all day, it's doubtful that you would do so pulling 200W continuously. It's more likely that a machine that stays on all time is running most of the time at idle (unless you Fold), otherwise the difference in energy consumed is neglegible.

However, let's assume for the moment that you do run at a constant 200W day in and day out. If this is the case, that would mean the rest of your system must be working overtime and generating a tremendous amount of heat (ie noise). So having a silent, fanless PSU won't make a difference in this case. Consider also that if you were to run a fanless PSU consistently at 200W draw, that the amount of heat generated would require more than just convection to keep the unit cool. So you would still need a fan running anyways.

(What warranty does the s12 ship with? If it's less than the phantom's then there's another thing to count against it)

Good point. Checking the manufacturers's published MTBF (Mean Time Before Failure) specs for an S12 500W and an Antec Phantom 500W reveals this:

Seasonic S12 500W - 100,000 hours MTBF

Antec Phantom 500W - 80,000 hours MTBF

So, the S12 has an estimated lifespan that is approximately 20% longer than the Phantom, according to manufacturer's specs.

The S12's fan doesn't aid air flow at all. Which means it's a fan spinning for nothing. With the S12 you have 2 fans going, the case and the PSU ones. With a Phantom 350 or a 500 (at low loads, probably slightly better than the review as you do have airflow directly over the PSU) you only have one fan going. With the 500 you will at worst have two fans acting in serries, rather than one doing nothing but causing turbulence.

I'm having trouble understanding your statement here. If the S12's fan isn't needed (ie the PSU is cool enough), then the fan shuts off. Also, if you're using an S12 in the P180, it's advisable to remove the Antec Tri-Cool fan in the lower chamber, as it is redundant.

Assuming we keep the Tri Cool fan in place, in both the cases you presented, S12 or Phantom, you have 2 fans in series. So how does the fan in the Phantom scenario aid in cooling while the fan in the S12 scenario hinder it?:?:

Bear in mind, I don't think that the S12 is perfect by any measure, but a good balance between silence, reliability, performance, features, and cost. Considering the other components in a PC, using an S12 in a build puts further PSU optimization way done on the priority list.

[jermaink]

Ths stability problems you mention also disturb me. I've read in many places about the freqency of problems with fanless PSU's breaking, even after only months of service. This may only be anecdotal evidence, but consider this: By removing an essential unit (a fan) for removing heat, the fanless PSU must rely soley on convection for heat removal. Heat is the enemy of virtually all electronic systems, so an increase in problems with fanless PSU's would not surprise me. If you add a fan to produce the air flow to remove heat from a fanless PSU, then all you've done is to turn a fanless PSU into a fanned PSU!

The stability problem I'm talking about is different to just plain quality or longevity. It's a particular problem with DFI Nforce 4 motherboards, which are extreemly picky in terms of playing nicely with PSUs. This appears to be a manufacturing issue, where some batches or something don't play nice while others do (sort of like how some Samsung Spinpoints are Nidec motor ones while others JVC).

Problem is discussed here:
http://www.dfi-street.com/forum/showthr ... ge=1&pp=15

[Bob_the_lost]

I'm having trouble understanding your statement here. If the S12's fan isn't needed (ie the PSU is cool enough), then the fan shuts off. Also, if you're using an S12 in the P180, it's advisable to remove the Antec Tri-Cool fan in the lower chamber, as it is redundant.
Assuming we keep the Tri Cool fan in place, in both the cases you presented, S12 or Phantom, you have 2 fans in series. So how does the fan in the Phantom scenario aid in cooling while the fan in the S12 scenario hinder it?:?:

Serries? You're getting confused here alright , the airflow for an s12 fan is in through the front of the case, over the HDs, then hits the back of the s12 and the airflow out the front of the PSU, then down and through the bottom of the PSU before being exausted out the back (mostly, some will be recycled as it will still exhaust in the wrong direction).

With a Phantom style system it's designed for the air to enter at the front and pass straight through to the rear where it's exausted from the case. You'll get reduced turbulence for a start.

Bear in mind, I don't think that the S12 is perfect by any measure, but a good balance between silence, reliability, performance, features, and cost. Considering the other components in a PC, using an S12 in a build puts further PSU optimization way done on the priority list.

It's the wrong layout for the P180, pull the cover off, reposition the fan at the rear and reshape the heatsinks and you've got a well suited option, but the s12 is the wrong design. The smart power II is the layout you want for the p180 http://www.silentpcreview.com/article260-page1.html

[MikeC]

It's the wrong layout for the P180, pull the cover off, reposition the fan at the rear and reshape the heatsinks and you've got a well suited option, but the s12 is the wrong design.

Despite the fact that a 120mm fan PSU is not optimal for the P180, we had no problems at all running S12 PSUs in the P180. (with the back extra vents around the PSU blocked off). Remember, an S12-430 was used extensively in P180 testing! It ran quietly all the time, and the drive temps were not an issue (even with the entire bottom cage full). See this page in the final P80 review on the main site: http://www.silentpcreview.com/article255-page8.html

[Ackelind]

Did it really run quiet all along? My S12 doesn't seem so quiet to me. I have a 120mm nexus fan at 5V and two Spinpoint P120 in my system, and still the S12 is the loudest component by far.

[MikeC]

Did it really run quiet all along? My S12 doesn't seem so quiet to me. I have a 120mm nexus fan at 5V and two Spinpoint P120 in my system, and still the S12 is the loudest component by far.

Yes, it did. A S12-430 was used, and Devon wrote this in the review regarding its noise with 4 HDDs in the lower chamber:

"...when the system was placed under load, the S12-430 had no problem exhausting the ~25W of heat produced by the drives, and its fan never ramped up audibly."

I've been saying since I first reviewed the S12-430 that it's the quietest (off the shelf) fan-cooled PSU I've run across, during testing in the thermal simulation box AND in actual use in a variety of systems.

Which S12 model? What's your ambient room temp? System components?

[Ackelind]

Strange that I don't have the same results.

It is an S12 430W model, bought here in Sweden. The rest of my system specs are in my signature. Everything is passive, so my only sources of noise are my 5V nexus fan at the back, my two hard drives and my S12. Last night i disconnected the power cables from both my hard drives, leaving my system with a failed boot screen over night, and then listening to the noise when I woke up in the morning (my hearing is a bit better then) and I could hear it even from 3-4 meters away. It isn't what I would call loud, but i can still hear it with low ambient noise.

My ambient temperature is around 25C, but my temps are fine and I don't think it is ramping up, the noise is not wind noise, but something more like motor or bearing noise, like a hard drive. The noise is not heard so much back at the PSU but more from the side of the case and when I'm a bit further away.

[MikeC]

Ackelind --

At this point, there are a couple possibilities:

1) The S12-430 is audible to you even though it is the quietest PSU out there. Maybe you have v. good hearing and/or very low ambient, which contribute to this. Have you compared it to anything else? We have. There are only a couple others that come even close.

2) Maybe your sample has an iffy fan. The ones I've heard aren't without some bearing chatter, but it's quiet enough that it's still better than anything else in actual operation (ie, not just at no-load idle).

The part that's a little odd is not that you can hear the S12-430, but that it "the loudest component by far". With 2 hdds, this seems abnormal.

[hmronin]

Serries? You're getting confused here alright , the airflow for an s12 fan is in through the front of the case, over the HDs, then hits the back of the s12 and the airflow out the front of the PSU, then down and through the bottom of the PSU before being exausted out the back (mostly, some will be recycled as it will still exhaust in the wrong direction).

With a Phantom style system it's designed for the air to enter at the front and pass straight through to the rear where it's exausted from the case. You'll get reduced turbulence for a start.

In theory, there may be reduced turbulence using a Phantom unit. However, whether this translates to measureable differences in temperature or noise attenuation remains to be seen.

The P180 case effectively removes several large heat sources (CPU,MB,VPU) that may influence the noise of the PSU fan. Because of this, the effectiveness of any given PSU installed in a P180 case will be largely dependent on its efficiency and the quality of the exhaust fan it has. Hard drive temps, and PSU ventilation design constitute secondary effects, which may or may not be detectable.

The S12 series of PSU provide an excellent balance of noise, performance, and reliability, all at competitive pricing. The Phantom is an excellent fanless PSU as well, but I'm not convinced that it provides anything more than the S12 doesn't already provide, and it costs more to boot. In fact, there are some caveats that make me think twice about fanless PSU's in general: higher cost, reliability, and in the Phantom 500's case, larger than normal dimensions.

It speaks volumes for me, when Antec incorporates a fan inside its "fanless" PSU product.