What Size Power Supply Needed

N

News Reeder

I am thinking the Antec SmartPower 380 or Antec TruePower

Asus A8N-Premium Motherboard
AMD 3800x2
Dual channel 1g ram 433mhz
PCI-E Video
160g SATA
200g SATAII
DVD Writer
DVD Rom

Sound OK?
 
B

BC

News said:
I am thinking the Antec SmartPower 380 or Antec TruePower

Asus A8N-Premium Motherboard
AMD 3800x2
Dual channel 1g ram 433mhz
PCI-E Video
160g SATA
200g SATAII
DVD Writer
DVD Rom

Sound OK?
Click to expand...


Probably not powerful enough, based on my experience trying to fire up
an Asus P5WD2 and a 3.2 Ghz CPU with a Seasonic 430W.

PC Power and Cooling (which is what I ended up getting) recommended a
510W unit.

Their web site also recommends a unit similar to the one I got for your
motherboard:

http://www.pcpowercooling.com/products/viewproduct.php?show=T51SLI

This, unfortunately, weighs in at $219.00. But, it comes with a 5 year
warranty.

Plugging in your equipment to their configurator, a Silencer 470 is
recommended. ($99.00) Three year warranty.

If finances are an issue, would recommend the 470 watt unit. If this is
a machine that will be used hard, and needs to be ultra reliable for
work, etc, would go ahead and get the 510 unit. Have used several
brands of power supply, PCPC units have always been the best, in my opinion.

http://www.pcpowercooling.com/home/


PS: no, I do not work for them.
 
B

bowgus

I went with the Seasonic ATX12V V2.0 600W ,,, very nice match with my asus
a8n-sli, 4000+, 2g ddr, 4 drives and single bfg7800gtx with probable upgrade
to sli.
 
D

Don Ocean

News said:
I am thinking the Antec SmartPower 380 or Antec TruePower

Asus A8N-Premium Motherboard
AMD 3800x2
Dual channel 1g ram 433mhz
PCI-E Video
160g SATA
200g SATAII
DVD Writer
DVD Rom

Sound OK?
Click to expand...

480w or higher for real continuous use and stability.
Check with Toms Hardware page.
 
N

News Reeder

Thanks for the info, and liks, it seems my system should pump well on a
350w, as after I listed all my specs, I was under 350w needed.

So, maybe going to a 380w would be safe area to be in.
but depending on cost, something higher for more power, might not be bad.
 
L

leadfoot

News Reeder said:
Thanks for the info, and liks, it seems my system should pump well on a
350w, as after I listed all my specs, I was under 350w needed.

So, maybe going to a 380w would be safe area to be in.
but depending on cost, something higher for more power, might not be bad.
Click to expand...

If the estimate was 350W I would be at least 100W over ie 450W You need
room to grow
 
P

Phil DeBecker

Thanks for the info, and liks, it seems my system should pump well on a
350w, as after I listed all my specs, I was under 350w needed.

So, maybe going to a 380w would be safe area to be in.
but depending on cost, something higher for more power, might not be bad.
Click to expand...

There is no way a 380w will do it. The A8N-SLI Premium is very power
hungry. You need an ATX 12V compliant power supply with dual 12V
rails and which puts out at least these amps:

40A on +5V rail, 18A on both +12V rails, and 30A on the +3.3V rail.

These current measurements are what's important, not the nominal
wattage of the power supply.

But you will not find a 350W or 380W power supply that meets those
amps. It is well worth the extra cash to get a good SeaSonic or
Antec 500+ watt power supply -- but before you buy, look at the specs
for the model you are considering and make sure the amps are adequate
on all the rails.

Phil
 
N

News Reeder

Im using an Antec case, will other non Antec power supplies fit the cases? I
know Antec makes a 480w crippers, that should be enough!
 
N

News Reeder

....Further to my last post... I see some PS come with single 120mm fan,
others with 2 smaller fans,

I am assuming that the 120mm blows down over the CPU area, but there is no
exhaust out the back? Where the dual smaller fans have one exhaust, and one
that blows over the CPU???
 
R

Roger Hamlett

News Reeder said:
...Further to my last post... I see some PS come with single 120mm fan,
others with 2 smaller fans,

I am assuming that the 120mm blows down over the CPU area, but there is
no exhaust out the back? Where the dual smaller fans have one exhaust,
and one that blows over the CPU???
Click to expand...
Fans on PSU's, should extract air, not 'blow down over the CPU'. Many
units have a single fan at the bottom of the PSU, blowing up through the
supply, and out through the rear of the casing, while others just have a
vent at the bottom, and fan(s) at the rear. The air flow direction is the
same in both cases. Generally, larger, slower fans are quieter than
smaller units, but the shape constraints of the case, prevent such a fan
being fixed to the rear panel.

Best Wishes
 
N

News Reeder

will most Antec power supplies fit in all Antec cases. I have a Sonata case
will the 550watt fit the same area as my 350w?
 
G

George Pontis

Phil said:
There is no way a 380w will do it. The A8N-SLI Premium is very power
hungry. You need an ATX 12V compliant power supply with dual 12V
rails and which puts out at least these amps:

40A on +5V rail, 18A on both +12V rails, and 30A on the +3.3V rail.

These current measurements are what's important, not the nominal
wattage of the power supply.

But you will not find a 350W or 380W power supply that meets those
amps. It is well worth the extra cash to get a good SeaSonic or
Antec 500+ watt power supply -- but before you buy, look at the specs
for the model you are considering and make sure the amps are adequate
on all the rails.

Phil
Click to expand...

That motherboard is not power hungry, it is that it enables use of two
power hungry video cards. With a modest video card and CPU, a SeaSonic
380W supply would certainly be adequate. The OP only said "PCI-E
video". If he is using something like a single Geforce 6600 or less
then there would no benefit to going with a large supply. Only extra
cost and fan noise.

Your current / voltage numbers work out like this:

40A on +5V rail -> 200W
18A on both +12V rails -> 432W
30A on the +3.3V rail -> 100W

Total 732W. Clearly that can't be the case - even the super gamer rig
with two of the hottest graphics cards and fast CPU would not exceed
300W demand from the power supply. To even approach that level, you
would have to be running a stress test while spinning up 2 optical
drives. The PC being discussed here is more likely to be closer to half
that demand, maybe 200W total demand on a bad day.

I concede that many supplies are over-rated and that the current
ratings must be considered. The best bet is to go with modern and good
quality supplies in an appropriate rating for the application. Few have
a configuration that _needs_ more than a S12-380. Those that are
running a P4 EE with dual SLI loaded with highest end video cards know
who they are and can go right to the 500W version without having to
think about it too much.
--
 
P

Phil DeBecker

That motherboard is not power hungry, it is that it enables use of two
power hungry video cards. With a modest video card and CPU, a SeaSonic
380W supply would certainly be adequate. The OP only said "PCI-E
video". If he is using something like a single Geforce 6600 or less
then there would no benefit to going with a large supply. Only extra
cost and fan noise.
Click to expand...

No, the motherboard IS power hungry. Read the manual, Asus themselves
recommend a 400W minimum for even modestly loaded systems.
Your current / voltage numbers work out like this:

40A on +5V rail -> 200W
18A on both +12V rails -> 432W
30A on the +3.3V rail -> 100W

Total 732W. Clearly that can't be the case - even the super gamer rig
with two of the hottest graphics cards and fast CPU would not exceed
300W demand from the power supply. To even approach that level, you
would have to be running a stress test while spinning up 2 optical
drives. The PC being discussed here is more likely to be closer to half
that demand, maybe 200W total demand on a bad day.
Click to expand...

Obviously, the numbers I quoted ARE the case, because those are the
capacities that Asus recommends. They do not mean that the PS will be
supplying that much current constantly, but that it needs to be able
to do so. If you look a the specs on any reasonable power supply
manufacturer's web site, you will see that most (but definitely not
all) power supplies of about 450W and up meet that criteria.
I concede that many supplies are over-rated and that the current
ratings must be considered. The best bet is to go with modern and good
quality supplies in an appropriate rating for the application. Few have
a configuration that _needs_ more than a S12-380. Those that are
running a P4 EE with dual SLI loaded with highest end video cards know
who they are and can go right to the 500W version without having to
think about it too much.
Click to expand...

The 400W power supply that came with my case was inadequate to power
my relatively modest A8N-SLI Premium system (single core 3800+, 1GB
RAM, single Geforce 7800GT, single SATA150 hd, dvd-rom, dvdrw). The
machine would lock up randomly several times a day. I replaced the
400W with a 550W Antec PSU which meets the specs I quoted above, and
have had no lockups since. The 400W itself was not defective, as it
is now doing just fine powering an older Athlon XP system.

Phil
 
P

Phil DeBecker

will most Antec power supplies fit in all Antec cases. I have a Sonata case
will the 550watt fit the same area as my 350w?
Click to expand...

Yes, it will. I have a SLK-3000BQE, very similar to the Sonata, and I
replaced the 400W that came with it with a 550W and it fit just fine.
ATX12V Power supplies in general are pretty much interchangeable, so
that a SeaSonic for example would fit into an Antec case without
difficulty. Higher capacity PSU's are heavier, but not any larger,
than lower rated ones.

As far as fans, PSU's with a single 120mm fan will have that fan
oriented so that it pulls air up and out of the case, not blow down
into it.

Phil
 
W

Wayne

I am thinking the Antec SmartPower 380 or Antec TruePower

Asus A8N-Premium Motherboard
AMD 3800x2
Dual channel 1g ram 433mhz
PCI-E Video
160g SATA
200g SATAII
DVD Writer
DVD Rom

Sound OK?
Click to expand...


I am using an Antec 380 watt TruePower (Sonata case) with an Asus A8V
Deluxe motherboard, with AMD 3500+ and four disks (two 80GB RAID, one
160 and one 320), plus 1GB RAM and Plextor DVD writer, etc. It is
nearly a year old and never any hint of any problem.
 
W

Wayne

IM thinking 550w is overkill, but it certainly future proofing.
Click to expand...

The numbers 380 or 550 are virtually meaningless. What is important is
the quality, if the supply can actually do what it claims or not. If it
can, 380 is more than enough. If it cant, 550 may not be enough.

Antec is a high quality brand, and their 380 likely outperforms the
cheap 550s. Search Google for Antec TruePower review
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Similar Threads

Right power supply? 3
600W PSU sufficient ? 12
A8N-Sli Memory Settings 4
A8N-SLi FAILED VGA TEST 8
A8N SLI Premium - SATA issues 4
Getting a new pc, specs inside. 6
New system stability 11
A8N-SLI 'Stop' Error 2

Top