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Several power supply questions

Posted: Wed Nov 11, 2009 5:45 am
by MrAl
Hello there,

I've been looking at power supplies for computers at several sites on the web, and have found
quite a variance in options.

Number 1:
Any manufacturers that are known to be better than others? There are so many manufacturers
it's just crazy trying to figure out which one is best it seems. I've also seen complaints about
the recertified power supplies too, that they sometimes dont work. Any ideas?

Number 2:
Anyone ever try running two separate power supplies for one computer to get a higher total
power? For example, one power supply to power the main board and drives and stuff like
that, and another power supply to power just the graphics card PCIe16 via the 6 pin connector?

Re: Several power supply questions

Posted: Tue Nov 17, 2009 3:56 pm
by reloadron
Home computer power supplies lead to a quagmire of a mess. There are name brands like Antec, PC Power & Cooling and a host of others that boast premium power supplies and other less popular names like Allied and a host of others that market less expensive power supplies. Most of these power supplies for home computers come from a few locations. Many come from Taiwan (Peoples Republic of Free China) or they come from Mainland China. Now if we board a plane and head for China I seriously doubt we will find an Antec, PC Power & Cooling or even an Allied power supply factory. What we will find are power supply factories much like these. Interesting is that those factories all seem to be located in "Province:Guangdong, China". I would venture many if not all occupy the same large building. These factories crank out millions of what I call plain vanilla power supplies. Naming conventions and fancy labels come later.

I have opened dozens of these creatures and frequently regardless of the name on the label found the same inner guts. Same components on the same vanilla boards. Other than some cosmetic differences they seem to follow coming from the same mold.

Something else interesting is the weight. You can take a more expensive brand name PSU rated for let's say 550 Watts and weigh it. Then weigh an off brand inexpensive PSU rated for the same output power and it will weigh less, sometimes a pound less. When we open them up I have found the more expensive brand name PSUs use solid copper for the main heat sink while the cheaper units use aluminum. I have also found the better PSUs seem to use better parts like higher rated capacitors. Unfortunately this does not always make for the better PSU.

I have some old cheapie PSUs here that still work fine and I have seen some newer brand name PSUs fail within a year. I have never dealt with refurbished. What I have learned is buying a better brand name PSU overall with all things considered seems to yield a better product with less chance of failure. Then too right now I am looking at an OCZ Technology OCZGXS700 (700 Watt PSU) that was in Kathy's machine. It failed after 2 years and this was not a cheap PSU. This one is a candidate for the MrAl PSU refurb treatment. When I have time I'll open this guy up. Since there was no smoke I am optimistic.

The overall conclusion is buy a reputable PSU with good reviews and pray.

Next as to running dual or multiple PSUs. Personally I favor a single larger PSU but when one has two PSUs and needs more power they can run a dual PSU configuration. Since the units have output regulation you don't want to parallel them but each can deliver to different loads. They trick here to keep things nice is to have them both power up and down at the same time or real close to it. A matter of slaving an auxillary PSU to a main PSU.When the main turns on we want it to turn on the aux and when the main shuts down we want it to shut down the aux. I like using a simple relay but a transistor could likely be used. There is a logistical problem with making things physically work out too but it can be done.


Re: Several power supply questions

Posted: Wed Nov 18, 2009 12:23 pm
by Janitor Tzap
I've run some El-Cheapo no names with out any problems.
And I'm currently running two Antec {5 year Warranty} units.
But yes, the better brand names are going to be some what better.
{But not always.}
I agree with reloadron that it is getting to be a crap shoot as to what power supply is best.
I normally check what the PC builders are using to get some idea as to what is a good supply.
I found that many will use a mid priced unit{Sparkle}.
Higher end power supplies, {Antec, Cool Power, EL-Power, Etc....}for game type computers.

Why are you interested in a dual power supply setup?
I go along with reloadron in saying;
Personally I favor a single larger PSU.
If you need more power for the system.

I have come across Hot-Swap-able duel Power supply setup for rack server computers.
But each PS had to be the same, you couldn't mix them.
Basically a redundancy setup, if one supply were to fail.
The other would still keep the server going.

Signed: Janitor Tzap

Re: Several power supply questions

Posted: Wed Nov 18, 2009 6:33 pm
by psycho
The PSU in my puter died about a month ago. I plopped in another one that I swiped out of my sons machine. I poked around on newegg and I finally decided to get this : ... 6817822002

It is really quiet and the cords coming out of it are in nice webbed looms. Very nice to look at - but it sits inside the machine so you can't see it... If you are getting another one, make sure it has all of the connectors that you want/need!


Re: Several power supply questions

Posted: Thu Nov 19, 2009 5:51 am
by MrAl
Hi there,

I hadnt thought about the weight factor. That might help to identify the
'continuous' rated PS from the 'max power' rated units. They are not always
too clear about that in the ads.
Yes, i intended to use a transistor for sync'ing the startup of the second
power supply. I think that would be a little easier than a relay and will
be faster too.
I'd like to hear more about your supply once you open it up, what you find and
what kind of caps, etc. Cap ratings would be interesting to know too.
The caps in the supply i repaired were either 10v or 16v rated, for +5 or
+12 respectively.

Oh yeah, Ron was saing that Antec is a pretty good name. I see a few of those
around on the web. I think i would have a little problem with a brand name
who's name was "Sparkle" ha ha.
So "Cool Power" is a good name too then?
I am thinking about using TWO power supplies mainly for a test. Let me
Ron had sent me a vid card that is pretty nice, but it uses about 80 watts
and may even use more peak watts for very short time intervals. With my
new power supply (came with the new case and only has a 17 amp +12v supply)
it causes the system to freeze up every so often, and one day it froze up
three times within about 2 or 3 hours. I since then took out the card and
figured that it was the lower power power supply that caused the problem,
but cant be 100 percent sure. Now i could buy a 500 watt power supply,
but if i go through that expense and it doesnt help that's a waste of money
so i wanted to be able to test the entire system with the card and another
lower power supply (16 amps on the +12v line) JUST to power the vid card
alone. That would power the pci-e-16x connector only. If the system
remains stable, then i would think a bigger power supply would solve
the problem and would eventually get a new one, but if the test fails
and the system still freezes up then i would not bother to order a new
power supply. That's the whole idea with using two power supplies, for
a somewhat short time test of maybe a week or two.
Hot swap/redundancy sounds nice too, but i dont think i want to go to
that expense right now.

That supply does look very interesting. I think im looking for 500 watts
min though, at some point. The reason is that i want to run a vid card
that uses about 80 watts and maybe a little more peak and possibly a few
other little things too. Not only that, but some of the power supplies wont
actually put out the rated power CONTINUOUSLY, but only for a short time.
I would like to get a continously rated power supply too if possible.
Yes the connectors are important. Would you believe i bought a new case
(sort of in a hurry cause my machine was down) with a power supply that
only has the standard peripheral 4 pin molex connectors? I didnt notice
at the time that it didnt have any sata connectors! Now i need another
power adapter :smile:

Re: Several power supply questions

Posted: Thu Nov 19, 2009 3:00 pm
by reloadron
Hi Ya MrAl

Using a transistor would be my choice. I suggest using a simple relay because most of the people in the computer forums I visit aren't quite electronically savvy and trying to explain to them how to make a little circuit using a transistor just wouldn't fare that well. :???:

Once I open that PSU I have sitting here I'll share the information. Before I removed it I did enough basic troubleshooting to say "yep, it's the PSU". The 5 Volt standby power was only 3 volts. When I jumped the PSU PWR_ON to common to force a start the PSU just made a clicking sound but would not power the system on. Since it was the wife's system rather than look for a working PSU in the junk pile I just went out and got her a new unit. Thing started fine. Replacing it was a nightmare as her system is tight and has a video card like a brick which was in the way. I remember when I built it a few years ago it was a nightmare and nothing changed. I sure hope the new PSU runs for a few more years.

Oh yeah, before I forget, if you need any four pin Molex to SATA power adapters let me know. I have a box of the things laying around here.


Re: Several power supply questions

Posted: Sat Nov 21, 2009 6:16 am
by MrAl
Hi Ron,

Sure i understand completely. I just wanted to mention the transistor in case anyone else
wanted to try this that had already done a little work in electronics.

I hope to get to try this soon but im doing a few other things right now.
Thanks for the power adapter offer too, i hope to be getting a few in the mail soon
as i just ordered two online :smile:

Re: Several power supply questions

Posted: Thu Dec 17, 2009 1:34 pm
by MrAl
Hi again,

I ended up with a Thermaltake power supply...that's a good name right?
I got a good sale on it and free shipping.