From PC Power and Cooling: Power Supply Myths Exposed!

[Jake_Barnes]

Re: PC Power and Cooling - "Power Supply Myths Exposed!"

I was looking through their site and read this "article". I found it interesting in that it contradicts some of the newer claims and benefits touted by other PSU vendors.

Look at:
1. Wattage Claims
2. Modular Plugs - A good thing?
3. 120 mm fans (?)
4. Single -vs- Multi 12 volt rails.
5. Single vs 2 fans (?)

I'd be interested in some of you opinions on these PCPC claims :?:

 

[Jake_Barnes]

No one interested enough or knowledgeable enough to comment :?:

 

[woshitudou]

1) Wattage Claims can be BS. You can claim 1kilowatt but not have enough amps to run a vid card and 3 drives.

2) Modular plugs, they're good so you can disconnect what you don't need.

3) 120 mm fan moves more air than an 80mm fan.

4) I think I prefer single rails even though I have multi. I have a feeling my 2nd 12v rail is overburdened while my primary is under used. I like the idea of having all the amps on one rail.

5) I live in a cool climate country so 1 fan is good enough for me. I could see two fans being useful if your ps is getting too hot.

 

[Jake_Barnes]

Did you read the article? Especially the part about modular plugs and 120 vs 80 mm fans - so I assume you disagree?

 

[grifter33]

As a general rule, I don't look too far into information provided by a company about their own products. It's very easy to paint things in a light that favors your own product while "discrediting" the virtues of others.

I'd rather get my info from an unbiased, impartial 3rd party.

 

[Slobogob]

Nice Thread. There were quite a few thinks i didn´t know.

 

[Jake_Barnes]

Nice Thread. There were quite a few thinks i didn´t know.

There are "guru's" that might not agree. I'm no expert, but I love a good, documented discussion ...

 

[buckiller]

Look at:
1. Wattage Claims
2. Modular Plugs - A good thing?
3. 120 mm fans (?)
4. Single -vs- Multi 12 volt rails.
5. Single vs 2 fans (?)

1) I personally have never thought about temperature's affect on power, but from my knowledge of engines i would now assume that they are right on this subject.

2) They don't tell us why resistance is increased when less is plugged in???? So this seems bogus, modular plugs are very usefull if you care about teh aesthetics.

3) A well engineered PSU with 80mm fan would certainly work as well/better than a poorly designed 120mm fan in a PSU. But the fact is most PSUs arent well engineered at all with many "hot" components far away from their ideal positioning. So yeah, if your going for high power a better engineered PSU would be better than one that just has a bigger fan. But if they actually did a study on various PSUs I think they would find the temps of the heatsinks would be about the same from 80mm to 120mm.

4) I don't know enough about this...

5) Extremely idiotic statement... looks as though they looked at 2 PSUs and made a generalization. Two 80mm fans put out a great more amount of air than 1 80mm fan... The small amount of space you lose to the additional fan seems like it wouldn't hurt the layout as much as a 120mm fan would, so this dual 80mm fan seems like the best cooling method for PSUs that are equally well laid out.

 

[Dante_Jose_Cuervo]

I've read this before. Now, I actually do agree a bit with some of what they say. Now, do take this with a grain of salt, I'm not completely versed in electronics... and this was written by them, so it is a bit biased, but consider this: how good are their PSUs? From what I know, the 850 and 1kW units are all tested at 50C for extended periods of time to make sure they'll be able to provide that full 1kW in a regular environment without any hiccups. Now modular cabling I don't like... simply because I'd lose all the cables.

Wattage claims? Just look at the Tagan turbojet 1000, they said 1100 watts max and yet they only got it around 800... if that. Personally, I use PC P+C, but that's just me.

 

[flasher702]

All the points they make are valid, but design and quality of individual PSUs is more important. As is the application.

Although their points on multiple rails are accurate, there are other considerations such as rail stability that cause me to favor multiple rails over single rails. If your CPU is on the same rail as your CD-ROM the CPU's voltage supply will fluxuate when you put a disk in. For most systems this shouldn't be a problem as the PSU shouldn't fluxate by much and the power regulators on the mobo should be able to handle it. For an OCed Over Volted system you need cleaner power to keep your components happy as they teeter on the edge of stability.

 

[sailer]

Look at:
1. Wattage Claims
2. Modular Plugs - A good thing?
3. 120 mm fans (?)
4. Single -vs- Multi 12 volt rails.
5. Single vs 2 fans (?)

I'd be interested in some of you opinions on these PCPC claims :?:

Ok, I used to work on electronics for the Air Force so I know a few things about wattage and so forth. Not everything by any means, but a few things.

1. Wattage claims are hard to follow, partly because there seems to be a lack of industry standards and/or advertised claims. But their point is lost until and unless they provide a charts showing their psus compared to other psus. Perhaps Tom's could do a specific study on this sometime.

2. There's nothing wrong with modular plugs. Used to use them all the time in the Air Force and still do in many places. They are (or were) very common in aircraft wiring. The power loss does need to be compensated for, but that isn't as big an issue as the article states. How many 2 foot lines do we have in a computer anyway? Beyond that, are the contacts gold, silver, copper, aluminum, or some other metal? What is the resistance of the wire itself? It makes a difference. Even further, think about the solder connections between wires, etc. Those have resistance also.

3. I really don't understand their beef with 120 mm fans. Ok, my present psu only has a 80 mm fan size, but why would putting a 120 mm fan on it make all the internal parts smaller? Unless you put the fan entirely inside the psu instead of on the surface, where part is inside and part is outside. Or are they implying that all psu's have the same external size? In reality, the 350wt psu in my oldest computer is about half the dimensions of the 680wt psu in my newest computer, so the 120 mm fan making the psu components smaller doesn't quite make sense to me, unless they're arguing the same external dimensions.

4. The idea of single vs multiple 12V rails looks like a red herring to me. Power doesn't get lost if all the wattage on a 12v rail isn't used. The power just isn't used. Multiple rails make sure that each component gets what it needs and no more. So they make one rail and split that rail to component parts. Why is that more efficient? I don't see an explanation. Another part, which I admittedly don't understand, is why they say in one sentence that "the maximum current from any one 12-volt rail of a multiple rail psu is limited to 20 amps (240v/12=20)", but for their psu, this is not a limitation. Ok, I may be lacking in my education here, but it looks strange to me.

5. The 1 vs 2, or even 3 fans is kind of a "So what?" argument. One fan to exhaust out the back, perhaps one fan to exhaust out the top, maybe one to blow air in if 3 are used. If multiple fans do a better job at cooling the psu, what's wrong with that? It seems to me like someone saying that he only has one fan to cool his PC and that people who use more than one fan are stupid. Maybe I'm missing something here, but it seems like only an argument raised to defend their having 1 fan instead of multiple fans.

Overall, at least some of what they say seems to be a case of blowing their own horn without providing any real proof of their claims. Until and unless I see a third neutral party doing tests to verify all their claims, I remain sceptical of the whole of their claims. There was some good information for sure, but also some of what I think is hot air.

 

[Jake_Barnes]

I'll invite PCP&C in to defend/debate this "article" - it's a good debate.

 

[croc]

Re: PC Power and Cooling - "Power Supply Myths Exposed!"

I was looking through their site and read this "article". I found it interesting in that it contradicts some of the newer claims and benefits touted by other PSU vendors.

Look at:
1. Wattage Claims
2. Modular Plugs - A good thing?
3. 120 mm fans (?)
4. Single -vs- Multi 12 volt rails.
5. Single vs 2 fans (?)

I'd be interested in some of you opinions on these PCPC claims :?:

First, this is obviously designed to promote PC& C, as it should be coming from their website... But lets go over the points that you've raised...

1. Wattage ... No real data (say from UL) presented, just their claims that PSU's fall off as they show on their charts.. So we are left to wonder what PSU's in general do under heat, and as well have to take PC&C's word that their TC 510 behaves as the graph shows.

2. Modular plugs. OK, I can buy that the plugs might introduce a few ohms extra resistance into the cabling. But if we followed the logic to its conclusion, all PSU's should be soldered in place. Personally, its a non-issue for me, as long as the modulars are well-made, good pins, etc., they MIGHT introduce a few mil ohms....

3. 120 MM fans. A top mounted fan for me will not work too well, as I generally have top mounted PSU's. Two 80's vs. one 80, or 1 one 120? I'd like two fans, as long as one was enough to do the job.

4. Single vs multi 12v rails. OK, maybe a valid point. Lose one rail, whether its a single or a multi, the PSU's most likely DED.

My 2p.

 

[clue69less]

Look at:

2. Modular Plugs - A good thing?

If you really worry about this, then you need to get Cramolin and regularly clean your 24-pin ATX connection, device Molex connections, etc. I mean, all of your PS connections to devices are modular, right? So you already tolerate those, so why does increasing the number of modular connections by 30 percent (assuming 24-pin and CPU power is hard-wired) make such a critical difference?

5. Single vs 2 fans (?)

When I tried my first Mushkin PS, I was worried about it having two 80mm fans, but actually they are quiet. Loud fans used to be the big beef against PCP&C (along with huge size and mass on their KW supplies), but they listened to the customer and found quieter fans.

I'd be interested in some of you opinions on these PCPC claims :?:

The bottom line to me is that they offer a range of wattages, the rails are rock solid and the ripple is low. I'd like them better if they were less expensive and had modular cabling as an option, but then again, I'd like alot of things I can't have.

 

[ikjadoon]

3. I really don't understand their beef with 120 mm fans. Ok, my present psu only has a 80 mm fan size, but why would putting a 120 mm fan on it make all the internal parts smaller? Unless you put the fan entirely inside the psu instead of on the surface, where part is inside and part is outside. Or are they implying that all psu's have the same external size? In reality, the 350wt psu in my oldest computer is about half the dimensions of the 680wt psu in my newest computer, so the 120 mm fan making the psu components smaller doesn't quite make sense to me, unless they're arguing the same external dimensions.

When your 350W is smaller than your 680W, that is in length, right? Like, it goes "deeper" in the system, closer to your optical drives? But, not in height, I imagine? All ATX PSUs are the same height. When you put a 120x120x25 PSU in the top, you are losing 25mm of space at the top, forcing you to make all your components a bit smaller. When you have a 80mm in the back, you are losing 25mm in the front of it, but you can make up that up by just making a longer at the back!

I never thought this was an issue, but..

I'd like them to defend it, see what they say..

~Ibrahim~

 

[jaguarskx]

1. Agreed. The efficiency of the PSU does have a direct impact on power usage. 80%+ efficient PSU are more commonplace now than they were a year ago. That’s probably due to Energy Star’s strict 80+ program. Electronic devices must consume less power while idling and at load to receive an Energy Star sticker (to the best of my knowledge).

2. Agreed. Higher temperatures do tend to decrease efficiency. Now I under why Antec claims their PSU are tested in 50C – 52C ambient temps. That’s the internal temperature, not the temperature of the room. If the ambient temp in the room was 50C, then there is no way in hell I would turn on my PC.

3. I would have to agree their claim about modular PSUs. While convenient, connection points generally have higher resistance than the wire itself, which can lead to a slight power drop. However, no one has really done any analysis regarding how much power is lost. For the moment; I’ll say it’s personal preference. I’ll stick with a traditional PSU.

4. I generally do not read all the fine print. But marketing hype is true for all products, not just PSUs. I did spend about 3 months of researching before finally buy my Seasonic S12 500 PSU last year.

5. Agreed. Who cares what the wattage is if you do not know how many amps each rail can provide at constant power?

6. I prefer a 120mm fan because it is quieter than a 80mm fan. That’s one of the reasons why the Seasonic S12 series is so quiet. I really have to strain my ears to hear the fan. However, not all fans are the same. The better fans tend to have lower acoustic characteristics while still being able to move a good amount of air (CFM). I think the S12 series uses an ADDA fan. Generic fans tend to be noisy even under low voltage. The exhaust from the S12 500 is actually quite when my system is being stressed (i.e playing a FPS game and encoding video at the same time)

7. I generally avoid 2 fan PSUs because of noise.

8. I generally agree that too many 12v rails can be a bad thing. A single rail that’s able to provide massive amounts of power is good so you don’t need to worry about balancing the power drawn from each rail. Having two 12v rails seems like a good balance. Three, four or more can lead to wasted amps.

 

[leo2kp]

owned

I happen to like my Hyper Type-R MODULAR PSU.

 

[buckiller]

Look at:
1. Wattage Claims
2. Modular Plugs - A good thing?
3. 120 mm fans (?)
4. Single -vs- Multi 12 volt rails.
5. Single vs 2 fans (?)

1) I personally have never thought about temperature's affect on power, but from my knowledge of engines i would now assume that they are right on this subject.

2) They don't tell us why resistance is increased when less is plugged in???? So this seems bogus, modular plugs are very usefull if you care about teh aesthetics.

3) A well engineered PSU with 80mm fan would certainly work as well/better than a poorly designed 120mm fan in a PSU. But the fact is most PSUs arent well engineered at all with many "hot" components far away from their ideal positioning. So yeah, if your going for high power a better engineered PSU would be better than one that just has a bigger fan. But if they actually did a study on various PSUs I think they would find the temps of the heatsinks would be about the same from 80mm to 120mm.

4) I don't know enough about this...

5) Extremely idiotic statement... looks as though they looked at 2 PSUs and made a generalization. Two 80mm fans put out a great more amount of air than 1 80mm fan... The small amount of space you lose to the additional fan seems like it wouldn't hurt the layout as much as a 120mm fan would, so this dual 80mm fan seems like the best cooling method for PSUs that are equally well laid out.

2) I now see what they were talking about, i misunderstood. I thought they were saying that haveing less plugged in is worse. When in fact they meant the items that are plugged in have that additional connection which DOES increase resistance. To consumers i think the aesthetics are more important than the tiny amount of resistance added to the system.

 

[clue69less]

If the ambient temp in the room was 50C, then there is no way in hell I would turn on my PC.

Sometimes you don't have a choice. About a year ago, my instrument was mounted in an aircraft that routinely had ambient temps in the high 40s for the first hour of the flight. At idle, the air in our controller PC would run in the mid-50s. It's a battle to keep stuff alive in that kind of environment but it can be done.

 

[sailer]

When your 350W is smaller than your 680W, that is in length, right? Like, it goes "deeper" in the system, closer to your optical drives? But, not in height, I imagine? All ATX PSUs are the same height. When you put a 120x120x25 PSU in the top, you are losing 25mm of space at the top, forcing you to make all your components a bit smaller. When you have a 80mm in the back, you are losing 25mm in the front of it, but you can make up that up by just making a longer at the back!

I never thought this was an issue, but..

I'd like them to defend it, see what they say..

~Ibrahim~

A couple things here. Maybe I should have said that the 350wt was REALLY old. None the less, it is smaller than the newer 680wt in all dimensions. A secondary thing is that there is a lot of room in my PC case for a fan to be sticking up high if need be. To help even more, I have the present psu mounted upside down, so if it stuck a bit farther into the case it wouldn't matter, assuming that the 120 mm fan was mounted on the outside of the psu.

My psu has two 80 mm fans and has no problem. I can't say by direct experience what a 120 mm fan would be like. But PC&C said they didn't even like two 80 mm fans, so my psu is bad by their standards.

 

[gm0n3y]

What kills me is how people won't hesitate to spend $1100 on a quad-core CPU (despite nearly no software that takes full advantage of it yet), or even $1200-$1300 on a pair of 8800 GTX's, yet bitch about spending more than $60 on a power supply! When I hear that whining, I just pray that the person has nothing but trouble with their system...

The thing you are missing here is that if you spend $1100 on a CPU or GPU, you will notice a performance increase compared to say a $500 product, but if you spend $300 on a PSU vs a $50, your PC runs exactly the same. So people just aren't very motivated to put money into that. I think until you actually have a cheap PSU fry something, you don't know the value of an quality PSU.

That being said, I don't think I will ever buy a P&C PSU. They are way too expensive. Don't get me wrong here, quality is important, at the moment I think my PSU is more expensive than my processor (AMD 3700 / Seasonic M12), but I don't think that the 'top of the line' PSUs are really worth it.

As for the modular claims, they are probably true, but I can accept a mild loss of power to keep my case cleaner. You may even gain the power back with increased airflow and lower temps in the PSU because of this (doubtful, but I can rationalize this all I want ).

 

[jaguarskx]

If the ambient temp in the room was 50C, then there is no way in hell I would turn on my PC.

Sometimes you don't have a choice. About a year ago, my instrument was mounted in an aircraft that routinely had ambient temps in the high 40s for the first hour of the flight. At idle, the air in our controller PC would run in the mid-50s. It's a battle to keep stuff alive in that kind of environment but it can be done.

Well, that's a special circumstance. But I agree, sometimes you don't really have a choice and you must manage heat as best as possible given the conditions.

 

[clue69less]

The thing you are missing here is that if you spend $1100 on a CPU or GPU, you will notice a performance increase compared to say a $500 product, but if you spend $300 on a PSU vs a $50, your PC runs exactly the same. So people just aren't very motivated to put money into that. I think until you actually have a cheap PSU fry something, you don't know the value of an quality PSU.

That being said, I don't think I will ever buy a P&C PSU. They are way too expensive. Don't get me wrong here, quality is important, at the moment I think my PSU is more expensive than my processor (AMD 3700 / Seasonic M12), but I don't think that the 'top of the line' PSUs are really worth it.

As for the modular claims, they are probably true, but I can accept a mild loss of power to keep my case cleaner. You may even gain the power back with increased airflow and lower temps in the PSU because of this (doubtful, but I can rationalize this all I want ).

Interesting analysis and I agree for the most part. The thing is, you can be on the edge with a power supply and have a computer that will start and run low power consumption apps just fine but then choke when current demand goes up. For example, my son's game box ran fine at stock clock on the CPU + GPU and could even handle a mild CPU overclock as long as the app was not too demanding. But if the GPU was goosed up much at all, it could not handle demanding games like Oblivion. The less demanding apps were fine with even a big GPU overclock. So I stepped up his power supply to a unit with over 40 amps on the +12 and it now runs fine in all apps with a 500MHz OC on the CPU and 200MHz on the GPU. So his PC did not run the same after going to a higher priced power supply - it ran better.

 

[leo2kp]

I too can't see why two 80mm fans wouldn't help at all. One intake, one exhaust, or both exhaust. More airflow is always better. I hope they're not saying that you lose heat-sink size due to adding more fans, because there are ways around that too.

I used to have a PSU that had 4 80mm fans. They were rather thin fans, but there was plenty of airflow and decent space for heatsinks. I replaced it because it didn't have the correct plugins for new video cards, and I didn't want to keep adding adapters here and there (thus cluttering my case even more). The PSU is currently in a friend's computer and running strong.

Their arguement that the fact people spot-cool their heatsinks means weak thermal management is completely stupid. IMO active cooling (fans) is far greater than passive cooling (bigger heatsinks), and having both big heatsinks PLUS a fan spot-cooling the hottest places would seem smart to me. I mean, doesn't that ultimately reduce temperature? Isn't that the purpose of thermal-management? And some of these PSUs have variable fan speeds which, in a way, simulates adding a larger heatsink. Aye?

You could totally go back and forth arguing every point they make. The only way to really prove something is to test it and document it.

 

[ikjadoon]

The thing you are missing here is that if you spend $1100 on a CPU or GPU, you will notice a performance increase compared to say a $500 product, but if you spend $300 on a PSU vs a $50, your PC runs exactly the same. So people just aren't very motivated to put money into that. I think until you actually have a cheap PSU fry something, you don't know the value of an quality PSU.

I think you hit the nail on the head there. People don't want to upgrade something that doesn't cause a performance increase. And yes, most of us are reactive vs. proactive.

~Ibrahim~