Power Supply

[boaz]

Hi,

Some power supplies have one large fan in the middle rather than 2 small
fans that Intel recommended.

Would you tell me what the advantage for using just one big fan in the
middle please?

Thanks.


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[Ghostrider]

Hi,

Some power supplies have one large fan in the middle rather than 2 small
fans that Intel recommended.

Would you tell me what the advantage for using just one big fan in the
middle please?

Thanks.

It is the volume of air that can be moved around that is
important. Smaller diameter fans have to spin faster in order
to move the same column of air was a larger diameter fan can
do at a significant slower speed. Slower the speed, less fan
noise, i.e., quieter.

 

[boaz]

It is the volume of air that can be moved around that is
important. Smaller diameter fans have to spin faster in order
to move the same column of air was a larger diameter fan can
do at a significant slower speed. Slower the speed, less fan
noise, i.e., quieter.

But the big fan in that kind of power supply is not in the back of the box
to suck the hot air out. That fan is blowing the hot air inside the
computer into the middle inside the power supply.

How does that work compared to the 2 fan power supply that suck hot air out?

 

[Glen]

Some good quality power supplies have a fan underneath the power supply
which suck air from the computer. There is a second fan at the back of the
power supply which blows the air out of the back of the power supply. This
has the advantage of increasing air coming out of the computer helping to
cool it.

If you are looking for a new power supply you should look to one of the
better known brands like Enermax or Antec or Tagan. They all make quality
parts better than looking for a power supply with a certain number of fans.

Tagan
http://www.tagan.com/

Enermax UK
http://www.enermax.co.uk/

Antec
http://www.antec-inc.com/

 

[antioch]

Hi,

Some power supplies have one large fan in the middle rather than 2 small
fans that Intel recommended.

Would you tell me what the advantage for using just one big fan in the
middle please?

Thanks.

Hi Boaz
It is suggested that a large fan i.e. 120mm is better than say two of 80mm -
shifts more air and is quieter.
Try and find a PSU with a decibel reading less than 19.
The lowest you can afford.
I swapped my PSU twin fan for a single 120mm - noticed the difference.
Rgds
Antioch

 

[bz]

How do you compare the 3 different Antec models?

The NeoHe has only 1 80mm fan in the back
The TruePower has 1 120mm fan in the middle
The SmartPower has 2 80mm fan - 1 in the back and 1 in the front.

I have a Cooler Master case with a 120mm fan in the back of the case right
behind the CPU.
Do you know which one of these 3 power supplies is best for my case?

It seems to me that the SmartPower is the best since it has 1 in the back
and 1 in the front. So, the 120mm case fan (right below the power supply)
will interfere with the power supply fans.

Am I wrong?

 

[antioch]

And what about comparing their power rates while you are at it -
300w/450w/600w?????
What about your case as well - how is it arranged - do you use an Intel
CPU - is it a case that fits their criteria.
Can a front of case fan be fitted for intake, or is it a side intake case -
how long is a piece of string?????????
You have only just started.
Do what I did - GOOGLE the problem.
Here is a start for you -

http://www.nonoise.org/resource/pcnoise/poweroid/poweroid.htm

http://www.almico.com/speedfan.php

http://www.pcworld.com/howto/article/0,aid,122111,00.asp

There are also DIY system building sites which help with power/cooling.
Happy hunting
Rgds
Antioch

 

[Tenshodman]

Whilst on PSU's I purchased a new Thermaltake 430 watt PSU as I was worried
my old one was getting a bit iffy. The old PSU is a no names 350 unit.
After replacing the PSU the system will not boot up properly sometimes even
the AGP card will only boot up to 120 out of the total 128 MB. Sometimes it
will boot up a bit further into the MB but then stops. The new PSU is a
switched one opposed to the old one. The MB is an ATX type with 1G P111 on
board. Any suggestions as to what could be wrong. I double checked all the
connection and yes the old PSU does have the extra 4 connection pin for a P4
but it is not used.

Cheers

Rod Gayford

 

[antioch]

Hello
Hope you don't mind me saying this, but you have hijacked a thread with a Q
different to this poster's - if you must do this then acknowledge first and
ask the poster.
Otherwise it can become very confusing with two questions being asked at the
same time, when trying to follow what is being written.
So if you have nothing to add to this thread re the merits of twin or single
fans in PSU's, start your own thread - please.
Rgds
Antioch

 

[Glen]

There is a comparison chart here.

http://www.antec.com/pdf/PSU_comparisontable.pdf

Use it to see the differences and choose a suitable model. The important
thing is look at how much hardware you have (or intend to have) and buy a
model powerful enough for your needs and has room to spare. If you are
thinking about dual high end graphics cards get a big power supply.

 

[boaz]

Hi,

Thanks for the link.

but the pdf doesn't tell why some units have 1 80mm fan, but some have 2
88mm fans, and some only have 1 120mm fan.

for example, it doesn't tell what the advantage to have just 1 80mm fan in
the more expansive model.

So... would you guys tell me how 1 80mm fan is better than 1 120mm fan or 2
80mm fans please? or vise versa... why 2 80mm fans is better than 1 120mm
fan... etc...

 

[antioch]

Hi Boaz
I think you need to do some research of your own - I have given some links
to sites as a starter - have you tried any of them yet - Google if you do
not get enough info.
You can also look in on some gamers site forums - power and cooling are
always hot topics.
You will get so much info you will not know what to do with it.
Also check with your case builder - tell them what bits you have/going to
have and I am sure they will suggest a suitable set-up.
Another consideration is, noise/coolness - which do you want to achieve?????
What are you going to use your system for - watching movies - gaming -
simming - surfing?
Rgds
Antioch

 

[boaz]

Hi,

The links do not expand anything regarding the size and the location of the
power supply fans.

What I want to know is why some power supplies... let's use the 3 Antec....

What I want to know is why 3 different Antec models use 3 different power
supply fans. What is the different. Is there one type of fan better than
the other type of the fan?

For example,
The top of the line NeoHe uses only 1 80mm fan in the back.
The cheapest SmartPower uses 2 80mm fans - one in the back and one in the
front.

Is using 1 small 80mm fan better than 2 80mm fans? or is using 2 80mm fans
better than 1 80mm fan?
What about the big 120mm fan in the TruePower. Is 1 80mm fan better than 1
120mm fan? etc...

 

[antioch]

Hi Boaz
Sorry, but I have gone as far as I can on this one - I think your Q's need
to be addressed to the manufacturers - all the different sizes etc are to do
with, the case type, where the PSU can be fitted in relation to other parts,
the hardware being fitted, price and accepted noise levels as a result of
the usage of the system.
Rgds
Antioch

 

[boaz]

They are all ATX power supply. So, they all have same dimension. But why
one has a big fan but the other has small fan. Why one has 1 fan but the
other has 2 fans?

 

[Ghostrider]

They are all ATX power supply. So, they all have same dimension. But why
one has a big fan but the other has small fan. Why one has 1 fan but the
other has 2 fans?

The only "standard" that has to be met for the ATX PSU is
for it to fit into an ATX computer case and that the screw
holes match up. The internal components of the PSU differ
amongst the manufacturers as well as their quality assurance
at delivering a specified amount of power with a specified
stability. How this is achieved depends on the components
that are actually built into the PSU. Some can be built with
with more efficiency than others. Those that are designed to
operate more efficienctly than others (for the same power) and
these do not need greater cooling. Cooling is achieved by the
air volume (e.g., in cfm). Put all of the factors together and
the fan variables RPM speed, blade count, fan diameter, etc.,
as well as the number of fans.

 

[boaz]

doesn't the Intel's recommandation says that the power supply need to suck
hot air out from inside the case? and it needs to suck air out next to the
CPU also?

This is the thing I don't get it. The newer power supplies don't seem to do
that anymore. They have big fan, small fan, 2 fans but... the fans are used
to cool only the power supply itself.

 

[Glen]

The very act of blowing air out the back will also suck air in from the
front and if there is a grille, from the bottom, just above the CPU.

I think you should email the power supply makers and see what they say. I
never really thought about it. If I think about it I would expect the larger
fan size overall to be better. That is 2 x 80 mm fans gives an effective
160mm which is bigger than 120mm fan. Look at the airflow CFM (cubic feet
per minute) and see if the amount of air changes in favour of bigger fans or
2 smaller fans that add up bigger than the bigger fans, if that makes sense.

There is also the noise element as larger fans create more noise so
manufacturers are reducing fans as much as possible but making them more
efficient.

Generally the more expensive the better the quality within a manufacturers
range. But that might not hold when you compare different manufacturers
units. One manufacturer might make a better quality power supply but make it
cheaper than another manufacturer.

 

[antioch]

Hello Glen
Reply intertwined/spliced etc

The very act of blowing air out the back will also suck air in from the
front and if there is a grille, from the bottom, just above the CPU.

I think you should email the power supply makers and see what they say. I
never really thought about it. If I think about it I would expect the
larger fan size overall to be better. That is 2 x 80 mm fans gives an
effective 160mm which is bigger than 120mm fan. Look at the airflow CFM
(cubic feet per minute) and see if the amount of air changes in favour of
bigger fans or 2 smaller fans that add up bigger than the bigger fans, if
that makes sense.

My understanding of fan sizes etc does not work like that - two small better
than one large?
Most articles written on this subject lean towards a larger fan i.e. 120mm.
and in particular as a case fan. A 120 will run at a slower speed and will
generate the same or slightly more cfm airflow than a 80mm fan running twice
as fast. In addition there is the noise factor if that is important.
Having two 80's will be much noisier than one 120 when either produce the
same airflow.
In addition, sleeved fans are almost silent compared to bearing fans.
On the downside, bearing fans will let you know if there is a problem as
they will get noisier over time. A sleeved will just stop operating
properly without warning and things will just get hot in the case.
Sleeved are of course more expensive.
A 120 fanned PSU is quieter and just as efficient as a two 80 fanned unit.
I know that because I swapped a two for a one PSU - and the 120 turns slower
and the temp reads the same as for the two fanned unit running at full belt.
I have yet to have the 120 running at a very fast rpm. The two 80 fans were
always running at a high rpm.

There is also the noise element as larger fans create more noise so
manufacturers are reducing fans as much as possible but making them more
efficient.

Now where did you get that idea from?? Thats not the way I have read
articles re fans/cooling/power.

Generally the more expensive the better the quality within a manufacturers
range. But that might not hold when you compare different manufacturers
units. One manufacturer might make a better quality power supply but make
it cheaper than another manufacturer.

Agreed - its a question of your 'pocket' - how much do you want to spend.
I have suggested the OP do his own research on this subject as I did two
years ago - contact manufacturers has also been suggested, which I did,
amongst other things. There are too many factors involved to come to a
definitive answer in one line.
I don't know about you but I feel 'brain-dead' - some would say I have had
this problem for a long time. But at my age I am entitled to use that as an
excuse for running out of ideas/steam, which I have on this thread.
Rgds
Antioch

 

[Glen]

Points answered below.

Hello Glen
Reply intertwined/spliced etc



My understanding of fan sizes etc does not work like that - two small
better than one large?

That is what I wrote. The overall larger size of two small fans increases
air flow.

Now where did you get that idea from?? Thats not the way I have read
articles re fans/cooling/power.

Noise has been a big issue for a few years now. You will see many hardware
makers removing fans completely and using heat exchangers of one type or
another. Search google and look around. While I dont think fans will ever be
removed from power supplies completly, manufacturers are trying to reduce
noise from them in various ways.

Agreed - its a question of your 'pocket' - how much do you want to spend.
I have suggested the OP do his own research on this subject as I did two
years ago - contact manufacturers has also been suggested, which I did,
amongst other things. There are too many factors involved to come to a
definitive answer in one line.

I agree, the op needs to get the best he can afford and more importantly
what's right for him and his computer. I also told the op to contact
manufacturers as they can answer specific technical questions.