PSU's---2 x 12v---The Dual Rail Myth

RemusM

Active member
LIEUTENANT COLONEL
Joined
Nov 16, 2006
Messages
2,188
The main tricks used by (many) power supply manufacturers:

1) advertising the peak wattage, rather than the nominal wattage
2) determining the wattage at unrealistically low temperatures (< 40C)
3) advertising total wattage as a measure of capacity, when modern systems are almost totally reliant
on the number of amps on the 12V line(s).

:grin:
 

Frankenputer

New member
GENERAL OF THE ARMY
Joined
Apr 16, 2004
Messages
9,815
I stumbled upon this and found it interesting:
http://www.ncix.com/products/index.php?sku=22898&vpn=DA750&manufacture=Silverstone%20Technology



 

Attachments

Rossoevo

New member
SECOND LIEUTENANT
Joined
May 12, 2005
Messages
209
Corsair TX750W test report

http://www.hardwaresecrets.com/article/505/5

So I just bought one !
 

ex_forum_user_3

New member
GENERAL OF THE ARMY
Joined
Jul 3, 2002
Messages
23,397
Hahahaha, first they tell everybody a splitrail is the next generation.
We told everybody they where wrong, even had some fights over this in the forum, heck even in this topic.
Now they are telling everybody single rail is the next generation, but in reality single rail is the "old school" :lol_anim:

The marketing spin doctors at work....anyway....we where right from the beginning and Intel was/is wrong...whoehaaa :lol_anim:
 

Frankenputer

New member
GENERAL OF THE ARMY
Joined
Apr 16, 2004
Messages
9,815
Thought you'd get a kick out of that Bas. I almost spit out my drink when I read that, :lmao: .
 

Stu

New member
GENERAL OF THE ARMY
Joined
May 25, 2004
Messages
19,551
Bas said:
@RemusM,

I would not put a Q-Tec in my office when I get it for free.
A UK magazine tested the 600W to see how good it was, it ate a well over 1000W to deliver it, sort of, but then to spring the 16A surge protector....
I wonder what would have happened if it did cut the power.
The testing magazine was http://www.pcper.com/

Can't find the article right now, but no way on earth I will ever use Q-Tec junk.
A noname cheap PSU is more trustworthy ;)
I remember showing you that article, you can see the Q-Tec review here:
http://www.custompc.co.uk/labs/79286/q-tec-650w-triple-fan-24p.html

They also reviewed a 'Generic 600w' model too: :lol_anim:
http://www.custompc.co.uk/labs/79283/generic-600w.html
 

mentat

New member
STAFF SERGEANT
Joined
Feb 17, 2008
Messages
51
Removed my kinda "dodgy" Dynamo Pro "600-watter" and bought the Corsair CMPSU-450VX because of this rave review: http://www.hardwaresecrets.com/article/540  :agrees: Unlike most generic, no-name power supplies this PSU is actually under-rated. :idea: It's supposedly "only" a 450W w/ a +12V@33A rail, but it was tested to be capable of ~570W and +12V@44A!  :biggthumbsup: Combined with a reasonable price, all Japanese-made capacitors spec'ed to 105?C, single +12V rail, non-modular cable design, and ripple-noise lower than the higher end HX- & TX-series, this PSU is a real gem. :worship: Heck, even the black case screws, plastic cable ties and case badge included in the box all exude high-quality...  :emot-tip-wink:
 

Aaron

New member
GENERAL
Joined
Nov 2, 2006
Messages
5,690
mentat said:
Removed my kinda "dodgy" Dynamo Pro "600-watter" and bought the Corsair CMPSU-450VX because of this rave review: http://www.hardwaresecrets.com/article/540  :agrees: Unlike most generic, no-name power supplies this PSU is actually under-rated. :idea: It's supposedly "only" a 450W w/ a +12V@33A rail, but it was tested to be capable of ~570W and +12V@44A!  :biggthumbsup: Combined with a reasonable price, all Japanese-made capacitors spec'ed to 105?C, single +12V rail, non-modular cable design, and ripple-noise lower than the higher end HX- & TX-series, this PSU is a real gem. :worship: Heck, even the black case screws, plastic cable ties and case badge included in the box all exude high-quality...  :emot-tip-wink:
It's Corsair. ;) They have the design and quality levels of PC Power & Cooling in my opinion. They rate the max output in normal operating temperatures (~50c) compared to most manufactures who rate their PSUs at peak wattage.
 

Fredrik

New member
GENERAL OF THE ARMY
Joined
Nov 24, 2003
Messages
16,121
This is a bit of off topic, but particularly bottom p 2 is interesting:
http://www.silentpcreview.com/article834-page2.html
 

Fredrik

New member
GENERAL OF THE ARMY
Joined
Nov 24, 2003
Messages
16,121
Found this on www.hardwaresecrets.com:

"This power supply uses a single rail design, so there is not much to say here. Antec EarthWatts 500 W, which is basically the same power supply with a different housing, uses a dual-rail design. The difference between the two is only how the OCP (over current protection) circuit is connected. On this power supply this circuit is monitoring all +12 V outputs at the same time, while on the model from Antec this circuit is monitoring two different sets of wires."
http://www.hardwaresecrets.com/article/540/5
 

Bernhard

Active member
GENERAL
Joined
Mar 17, 2009
Messages
6,248
Just like the hundreds of memory issues, the PSU issues continue to be suspects in a lot of the technical queries related to motherboardsand Graphics cards. It has actually become a very confusing market for the general user ever since high power PSUs became an issue due to the inreased power demands of the "high" end home PC, and when I say "high power" PSU, I mean more than 500W. Doesn't sound that much but when one talks about half a kilowatt, only then does one realise what little power stations our everyday computers need. So the manufacturers started the novel idea of seperate 12V rails for stability and to prevent spiking and surges. And this is where the normal customer who actually has limited knowledge, (hopefully) looks at the amps and sees e.g. 41 Amps or 500W total on 12 V. The fine print though will clearly show that possibly 18A per rail is the max, meaning that utilising 2 of those rails limits the PSU to 36A for the GPU alone if two 12V rails are used. Thus the user has 4 12V rails, each capable of 18A individually, but as soon as he maxes two rails, in reality he has 5Amps left for the other 2 rails.
A similar single rail PSU would probably provide 50Amp or more on a single 12V output. Yes its all shared, but at least the "Juice" doesn't run out as early.
Admitted, they both have their advantages and disadvantages, but when we get to power delivery, the one advantage of the total amps available on 12V in my opinion outweighs the others. This does not go without saying that the customer should still do his homework in terms of stability and efficiency.

I sometimes wonder how many system instabilities are really caused by a lack of power or even unstable power delivery. Yes, we all expect those wonderful power circuits on the boards to manage a stable power delivery, but we seem to forget that any component/circuit, even on the best boards have their input limits. Hopefully the system will shutdown when the input is outside the limits, but how may times do we expect these circuits to protect the rest of the components, before they themselves have had enough? Even worse, I wonder how many boards have been RMA'd because of damage done to them due to power supplies that are just not up to scratch, and the manufacturers assume responsibility for component failures caused by the PSU without having any proof.

I always read with interest the hardware reviews with regards to PSUs and especially those where the tester actually ensures that the unit is tested to its claimed maximums to establish the real values and stabilities. It is actually frightning how many of the so called "better" supplies fail or are just inside the margins. One has to feel sorry for people that actually buy pre-assembled units which are built into a case that already contain a "No Name" 250W or 350W PSU.I still remember my first Intel machine that I bought in similar fashion, and later I upgraded and found that the 12V rail would actually fluctuate from 11,2 up to 12,3V.

It's amazing how much money people are prepared to fork out for high end boards, CPUs and GPUs and then save a couple of dollars on the PSU. It is not dissimilar to someone buying a super car, e.g. Ferrari or Lamborghini and then filling it up with regular unleaded.
My only wish is that people would pay more attention to buying the correct driving force behind the high tech components that they envisage to power with whatever PSU they choose. But then again, I suppose most forums are reactionary instead of being a place where ordinary people would enquire before buying and mixing and matching. 




 

ex_forum_user_3

New member
GENERAL OF THE ARMY
Joined
Jul 3, 2002
Messages
23,397
Merged into this topic as it's being discussed for a long time now.
No need to start another one.
 
H

Henry

Guest
ZSDE, I don' know if you've noticed but there are some of us here who will let someone know right off when we spot a questionable PSU in their specs but often as not they will reply with something like: "It works so don't tell me it's no good". These are sometimes people with over $1000 invested and then put in a crappy $25 PSU.
 

ex_forum_user_3

New member
GENERAL OF THE ARMY
Joined
Jul 3, 2002
Messages
23,397
For the fun of it a 1050W Powersupply "splitrail" see how marketeers fool people REAL BAD!

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=187

Enjoy as I laughed my head off :lol_anim:
 
H

Henry

Guest
:rofl2:

I can't wait to see that sorry piece of crap to start showing up here. It just has to be a re-badged Q-Tek
 

ex_forum_user_3

New member
GENERAL OF THE ARMY
Joined
Jul 3, 2002
Messages
23,397
Henry, to laugh even harder:

http://www.diablotek.com/index.php?option=com_content&view=article&id=58&Itemid=72

About Us

aboutus

Founded in 2003, Diablotek. is one of the nation's most recognized Power Supply and component Manufacturers and has relationships with all of the top computer component companies in the world including Intel, AMD, NVIDIA, ATI, and many more. Diablotek builds some of the most highly regarded computing solutions in the industry for demanding customers who need the highest performance machines with the most reliable components.

Diablotek's years of experience focused in Thermal IT and cutting edge power conversion technology has provided timely and professional solutions to meet and exceed many of the ever growing IT industry's and consumer requirements.

With our comprehensive line of products available today, it enables Diablotek's customers to enjoy the power to do more in a one-stop-shop experience. Each one of Diablotek's strengths enables its customer to focus on their core business while taking advantage of the skills and efficiency of a cutting edge technology making diablotek your first choice solution partner.
Hahaha, their building doesn't even have their own brandname on it and their domain registration has a HOTMAIL address :rofl2:
You are right, it must be Q-tec rebranded junk.
 
H

Henry

Guest
Take a look at the video cards they claim to sell. They picture a fairly recent one but click on the link and the 3 they have are ancient, The RAGE 128 PRO 32MB, RAGE XL 8MB, Radeon 7500 64MB :worship: the Gods of antiquity. ;D
 

wlahdone

New member
MAJOR
Joined
May 31, 2008
Messages
1,030
I simply hate overrated PSU-s ,they fool customers.It barelly has half of the specified ,pff.
 

DaLoona

Active member
MAJOR
Joined
Aug 10, 2007
Messages
1,242
:deadlaugh:  something "split" alright in that psu review from Johnnyguru

I guess if your a fan of its aesthetics, you could always use it as a paper weight  :lol_anim:

:emot-tip-wink:
 
You must log in or register to reply.
Top