question about +12V rail

E

eyebunnn

n00b
Joined
Jun 15, 2004
Messages
29
I have a cheap PSU that came in with my case. It has:

5V = 25 A
12V = 15 A
3.3V = 20 A

When I view my power stats, everything seems to be right where it's supposed to be except the +12V line. It fluctuates from around 11.40 - 11.58, no more, no less. I got two questions:

1) is this normal??

2) if not, should I be worried and shell out $$ for a new PSU?

Thanks everyone
 
Get out the multimeter and test it yourself; Software-based monitoring programs are bad at determining exact voltages, so it is possible that you're +12v is right on the money.
 
the acceptable range for the ATX spec is 10.8 to 13.2
so if it accurate..
however there is a much larger amp load on the +12V these days
(and the spec actually morphed more or less, a new spec proposed and only partially adopted ATX12V)
and many of yesteryears PSUs arent really up to it (depending)
when you really need those amps is when your spinning up the drives and fans
and of course software monitoring isnt typically available at that time

could I ask what its powering and what make it is?
 
wow... thanks for the quick reponse u guys...

Ice Czar, it's a generic PSU that came in with my case. It's called Cybermax and it's rated at 350 W.

This is my setup:

MSI K7N2 Delta-L
Barton 2500 OC'd to 3200
1 stick Hynix PC3200 DDR
1 8 gig WD 5400 rpm
1 80 gig Maxtor 7200 rpm
Soundblaster Live Value
LG 16x burner
a floppy
3 Case fans
Logitech Rumblepad
Cordless Mouse
+ your usual microsoft keyboard/mouse optical combo
 
generic
strike 1, 2, 3 your out :p
well that would be my first take,
for starters the test proceedure to derive the above amp numbers would be highly suspect
the 3.3V and 5V likely being combined, but tested independently (looking at them make that definately tested seperatey)
and then the value employed to determine what an acceptable sag would be is probably
blowing a fuse, the max amp and watt figure is likely only good for a few seconds, and the whole shooting match tested at 25C when your normal operating temperature is 40C
which would decrease the watts available be 1\3rd or so

balance that with
when you add up the rails (amps per rail) for a given component its the theoretical maximum, and then those are all added together, which in real life would be highly unlikely
(that all the components are at full power at one time)

so here is a good calculator and an article
Choosing the right Power Supply &
takaman's Power Supply Calculator rev0.61x
to determine the amps you need per rail

also review
http://hardforum.com/showthread.php?t=763701&highlight=Choosing

Im just guessing on alot of this stuff but came up with

5V = 18.8 A
12V = 15.9 A
3.3V = 2.4 A
with a combined 3.3+5 of 102Watts
for a total output of 303Watts

if youll look at that last link youll see there has been an increase on the needs of the 12V rail
and yes that would be a concern
considering Id bet those specs are complete BS
 
I hate to be a spoiler but would you risk that valuable sys on a cheapo PSU that can actually do some serious damage and if your lucky,just cause minor problems like rebooting and sys hangs..many a system has been fried buy someone trying to save a few $ and cutting corners..you'll feel alot better knowing you have a quality *heart* feeding your system when you invest in a PSU that equals your system and if your a OC'er..it's not even an option. :)
 
my from affordable to expensive recommendations
Fortron Source \ FSP Group $39 (350W FSP350-60PN) and thats cutting it really close
but they overestimate their rails quite often, Id jump up to a FSP400-60PNU-RI but that puts you into $65, if your case temp is really low it would do probably, but leave you with littel room for growth, but at $65 you might as well get the Antec)
Antec True Power Series $69 (True 430W)
PC Power & Cooling $200 (510W Turbo Cool)

newegg has the first 2 (and is the source of the prices)
the PCP&C could be had from them dirrectly and the Deluxe is the same price
(PS its rated as a 600Watt at the temperature the other 2 where likely tested at 25C, it rated 510 @ 40C)

the Voltage Regulation on the PCP&C is 1%, the Antec 3%, and the Fortron 5%
 
eyebunnn said:
o man, im broke already as it is..... BUT since you guys insist generic PSU's are crap, yea yea i know... I'm taking a look at the SilverStone SST-360. I've google'd it and came up that it ain't a bad choice, being cheap and all. Anyone have any experience with the SilverStones?
Click to expand...
Do you use MBM5? If you do, did it function properly showing all voltage levels correctly in your mobo? do you have prime95? Do you have cd/harddrive performance benchmark programs?

If the above are YESs, you should learn how to use the readings of MBM5 in finding out if your current power supply is already more than sufficient for what you are doing.

1) is this normal?? YES, IT IS NORMAL.

2) if not, should I be worried and shell out $$ for a new PSU? There was nothing to worry about.
 
nam-ng said:
There was nothing to worry about.
Click to expand...

didnt read the links did you?


and just to reinterate this point one more time
http://www.anandtech.com/showdoc.html?i=1774&p=8
"the majority of damaged RAM returned to memory manufacturers is destoryed by fluctuations in the voltage."

Power supplies become increasingly expensive June 13, 2004

He explained that the later P4 CPUs take their power from a 12 Volt feed and, using the onboard voltage regulators, generate the high current, low-voltages they need to operate (anywhere from ~ 1.6V to around 2.7V). So the first requirement is a PSU that has plenty of power available from the 12V supply. Since the older ATX compatible PSUs didn't supply much current from the 12V section you have to ensure that your new PS delivers enough current (or power in Watts) from the 12V section. That's why using your old P3 ATX PS is a big "no-no".

He then described the history of the post-P3 power supply mess:

The earlier Athlon motherboard manufacturers decided to solve the 12v problem by using an additional 4-pin square connector to get the extra 12V those CPUs required. However many older PSUs didn't provide the 12V 4-pin square connector.

The motherboard makers then wised up and decided that there was nothing magical about a square 4-pin connector, so they put a normal hard disk type socket on the motherboard and provided the 12v power via a standard hard disk (4-pin inline) connector. Problem solved - you may now use your older PSUs provided they supply sufficient 12V current (many did not).

Further confusion came from PSU manufacturers not specifying the capabilities of the PSU in a way that allowed the end user to verify it's 12V power output rating.

In the meantime the ATX spec was saying "use the new 6-pin" inline connector - and very few motherboard makers implemented it.

Just to be sure, some motherboard makers, implemented *both* the hard disk style 4-pin inline connector and the square 4-pin connector. They said "use either or both in any combination you like".

The spec then evolved to the 24-pin main connector. Again, most motherboard manufacturers did not wish to make their customers mad by mandating that they replace their power supplies. This might cause their customers to avoid motherboard upgrades. Some used a "special" 24-pin connector with the extra 4-pin connection blocked off, or colored so that the user could plugin a 20-pin plug into the correct end of the 24-pin socket on the motherboard. Many others simply ignored the 24-pin requirement in the specs. Again - problem solved - use your older PSU.
Click to expand...

there is a reason to be concerned
namely the investment he has already made
MBM isnt avialble to monitor the voltage instabilities so common at startup

for example a Codegen 300X1


compared to an Antec True Power 480


or a PC Power and Cooling 450


the above from
http://terasan.okiraku-pc.net/dengen/tester/index.html
http://terasan.okiraku-pc.net/dengen/tester2/index.html

when your spinning up all the drives and fans, it takes 4 to 5 times the amps
and there isnt any way to monitor that except a multimeter (which the above charts are a log of) and those drives and fans are using the +12V

so it really depends on how well the onboard voltage regulation scheme is implemented
and these are the same manufacturers that not that long ago, used capacitors just slightly cheaper than their old source to disastrous effect, and I know of no one that is testing the implementation of mobo volatge regulation, as the testing would destroy the mobos

so its smarter to be as "tight" as possible on the PSU end
PSU A in Mobo A does fine, but in Mobo B stuff can fry
(and this is just one link in a chain, add in unstable power from the utility, then the transient response isnt the issue, but the Voltage Regiulation spec, and generics are rarely good at dealing with that
 
didnt read the links did you?
Click to expand...
I have done quite a few switching power supplies in the last 15yrs.... from 3V -> 80KV, from 1W -> 2KW. don't see any sense in reading some newbie guides..
 
then you should have been aware of the ATX standard snafu
and had him throw a multimeter on the PSU to actually determine if there is the need for a new one, your not the sole EE in here BTW

and we are actively seeking such expertise as yours :D

a bit more
Winbond Launches New Bus Termination Regulator April 4th 2003

"Winbond Electronics Corporation, a leading supplier of semiconductor solutions, today launched the W83310S, a new DDR SDRAM bus termination regulator. The solution, new to Winbond's ACPI product family, is aimed at desktop PC and embedded system applications with DDR SDRAM requirements.

Computer systems architectures continue to evolve and are becoming more complex; CPU and memory speeds continue to increase ever more rapidly with every technology turn. More and more high current/low voltage power sources are required for PC systems. This is particularly true for high-speed components such as CPU, memory, and system chipsets. The performance of these components is highly dependent upon stable power. Therefore, motherboard designers require accurate, stable, low-ripple and robust power solutions for these components.

Many system designs use discrete components to implement bus termination functions. This approach creates several problems including poorer quality load regulation; higher voltage-ripple, increased usage of board space and inconsistent designs when different discrete components are used."
Click to expand...

standard snafu + increased need for stable power + cheap PSUs = alot of fried stuff
see instabilities and blown components in here every day
 
I don't care what anyone's titles are, only the contents of their postings.
 
It was not I who assumed everyone they met an ignorant newbie. I only do so after repeated indicators, over and over and over.
 
LOL

maybe you should assume that there is going to be a very large portion of the people who will view this that are :p
 
nam-ng said:
don't see any sense in reading some newbie guides..
Click to expand...


I would in this case beg to differ :p

but wed really like to get even more expertise for this forum ;)
Ive already got gee working on a few FAQs and Maklar has cobbled together a nice Isolated Ground Plug Tutorial

(gee is an EE w\ switching power supply and UPS design experience, and Maklar is an Electrician, and they might have more qualifications, havent really grilled them :p )
 
nam-ng said:
Perhaps that is advanced reading for you, it is a newbie guide for me.
Click to expand...

Help those not quite as advanced as your self. Noone here is impressed by bragging.. Most are impressed by more knowledagble folks (such as yourself apparently) helping those that don't know as much.
 
LOL granted its not "technical" but then its not supposed to be

it does however contain the pertinent information applicable to this thread
that there is a reason for concern, do to the "marketing" mindset adopted by
mobo manufacturers coupled with the prevelence of the last gen of PSUs and crappy modern PSUs

technical expertise doesnt cover the "situation in the market"
and there are a large number of variables with all the various components
but in general, yesteryears PSUs often fall short, and can place modern mobos at risk
especially in here (another area of consideration)
where overclocking, case modding (with tons of accessories)
and the trend towards running larger numbers of drives than many a NAS, is pretty common ;)

we may not all be EEs
but there is a large amount of empirical evidence available in here ;)
 
SKiTLz said:
so politely.... pull your head out your ass and help those not quite as advanced as your self. Noone here is impressed by bragging.. Most are impressed by more knowledagble folks (such as yourself apparently) helping those that don't know as much.
Click to expand...
Start from beginning of this thread, read it over and find who wanted to impress who.

I did made the very first post to help, the rest of it was a waste of time RESPONDING to "titles", "impress", "bragging", and your idiocy.
 
cool it

flaming is NOT allowed
and will get both of you and this thread locked down
 
I already know it is normal for most places that low-life idiots are to be allowed, though rarely that talking to low-life idiots are permitted.
 
so are you just a troll here to stir up trouble
or do you think you have something to contribute?
 
I did in this thread with the first post, the rests are responses to your querys and the one idiot above.
 
Post has been edited. Sounded quite appropriate however if you ask me. Wasn't so much flaming, more the truth.

Its quite obvious nam-ng doesn't want to contribute on the level of us common folks. Maybe when we reach a higher level??

Your first post was helpful, too bad you couldn't keep it up.
 
nam-ng now has 24 hours to reflect on The Rules here and work on an attitude adjustment before being allowed to post again.

And SKiTLz, you were close to joining him. In fact, you did for a minute til I saw your last response. Please people, don't take the bait. It'll just get you in trouble as well.
 
nam-ng said:
Perhaps that is advanced reading for you, it is a newbie guide for me.
Click to expand...
Nam-ng,don't feel so insulted or hurt simply because other's also have opinions..I read your posting history (12 messages) here and you have not gone into *any* detail whatsoever with your posts,maybe you should try and be alittle more helpful and detailed since you make the point that you have so much experience with PSU's. I have to wonder why you had problems after only 12 posts..is this typical?

..no answer required..I'll look forward to your future insite on issues your experienced with just don't treat everyone like noob's even if we are. :)
 
whoa that was something...... ok this will be my last question u guys... sorry for being so stubborn but i'm really REALLY strapped for cash and the antec Ice_Czar recommended will cost me $109 canadian. OK, i will be getting rid of my 9600 pro in the next month and replacing it with an ancient ATI RAGE 128 (wooooo!!!) since I will be off to university and have no time gaming.

1) Will this be enough for my el cheapo PSU to handle??

2) I don't really care it my whole setup dies in 3 years since I get new parts every 3 years so do you guys think my generic PSU can keep my setup alive for the next 3 years?

The only reason I'm asking is that I've yet to witness PC components getting fried by generic PSU's.... I've built 5 PC's now and all of them in generic PSU's... no problem whatsoever.. very stable. But after reading stuff in this forum, now I'm all worried.... it's hard being broke... believe me... Thanks for the input.... Ice_Czar and nam-ng specifically.
 
run your rig with the new (old) video card through the calculator again
the short answer is probably, as I mentioned before, the theoretical power required and the actual running draw is substantially different
but if you develop intermittent problem, corruption, and or start frying RAM
or cant get your overclock stable from one day to the next
that would be the likley culprit as your close on that 12V rail

Id trust that Fortron alot more than the Cybermax
and OCing with that is problematic,
you really want as much stability as you can get ;)

and there are always older "high quality" PSUs with a higher capacity
either in For Sale\Trade Forums or even ebay


Good Luck :D
 
eyebunnn said:
whoa that was something......2) I don't really care it my whole setup dies in 3 years since I get new parts every 3 years so do you guys think my generic PSU can keep my setup alive for the next 3 years?

The only reason I'm asking is that I've yet to witness PC components getting fried by generic PSU's.... I've built 5 PC's now and all of them in generic PSU's... no problem whatsoever.. very stable. But after reading stuff in this forum, now I'm all worried.... it's hard being broke... believe me... Thanks for the input.... Ice_Czar and nam-ng specifically.
Click to expand...

I just checked newegg refurbished bin and they have a Aopen (Fortron) 350w for just $32 add $1 for shipping (not sure Canada shipping) and you have a bargain bin price on a quality
PSU...just depends on your circumstance though. :)
 
justin_credible said:
Nam-ng, don't feel so insulted or hurt simply because other's also have opinions..
Click to expand...
Don't attribute what's yours to another, the internet is diverse and wide. Not all of us subscribed to typical convention... much less Modern, Western, nor American convention.

I read your posting history (12 messages) here and you have not gone into *any* detail whatsoever with your posts,maybe you should try and be alittle more helpful and detailed since you make the point that you have so much experience with PSU's.
Click to expand...
Go ahead, be more detailed and more helpful to eyebunn. I'll not stop you, how you wanted do it is your business and not mine. If you can do a better job all the merrier.

I have to wonder why you had problems after only 12 posts..is this typical?
Click to expand...
Yes, for me it is typical. Some wanted to be different, some tried to be different, and then there're some liked me who are borned to be naturally different.

For example, I could give an answer in this THREAD since it was and is stuck in never never land for more than 2 weeks as of today. I'd avoided it, as the answer more likely than not would cause problems.

Because my answer for that one will not be like any of the others already posted by other experts. Yep, it would definitely BE DIFFERENT.

..no answer required..I'll look forward to your future insite on issues your experienced with just don't treat everyone like noob's even if we are.
Click to expand...
Don't look forward to it, I visited these forums since the beginning without ever making a post until recent.

"It was not I who assumed everyone they met an ignorant newbie. I only do so after repeated indicators, over and over and over."

EXAMPLE <-- I gave the answer in the simplest possible manner but not given the work-around solution. Anyone not an ignorant newbie who understood the answer would come to the expected work-around solution without hand holdings. The answer was not made under the assumption that everyone I met automatically an ignorant newbie, those wanted further more could ask for further more.

Adieu, CYA somewhere on the net.
 
nam-ng said:
Yes, for me it is typical..
Click to expand...

interesting example, however your navel gazing isnt on topic
if youd like to address the topic, provide an opinion, offer a rebuttal
or refute a claim regarding the topic, do so.

Otherwise, refrain from posting in this thread about your personal observations
of other members, or your percieved persecution as a misunderstood and unappreciated
font of knowledge

some how I doubt youll take this additional opportunity
but I thought Id offer it once more, it is meant sincerly ;)
 
You must log in or register to reply here.
Back
Top