PSU Rails 1,2,3 ??? - Techist - Tech Forum

Go Back   Techist - Tech Forum > Computer Hardware > System Upgrades
Closed Thread
Thread Tools Display Modes
Old 02-06-2008, 06:15 PM   #1 (permalink)
Newb Techie
Join Date: Feb 2008
Location: S. Central Mich.
Posts: 5
Default PSU Rails 1,2,3 ???

Hey all
Was wondering what the difference is in # of rails and do they all hook up the same,Work the same,etc....

dalejiw25 is offline  
Old 02-06-2008, 06:42 PM   #2 (permalink)
Do not Stare at my Avatar
Ste's Avatar
Join Date: Aug 2005
Location: Upon Gleaning Infinity
Posts: 9,571
Send a message via MSN to Ste
Default Re: PSU Rails 1,2,3 ???

Power Supply Myths Exposed!
With all the hype about multiple 12-volt rails (ads claim that two rails is better than one, five is better than four, etc.), you'd think it was a better design. Unfortunately, it's not!

Here are the facts: A large, single 12-volt rail (without a 240VA limit) can transfer 100% of the 12-volt output from the PSU to the computer, while a multi-rail 12-volt design has distribution losses of up to 30% of the power supply's rating. Those losses occur because power literally gets “trapped" on under-utilized rails. For example, if the 12-volt rail that powers the CPU is rated for 17 amps and the CPU only uses 7A, the remaining 10A is unusable, since it is isolated from the rest of the system.

Since the maximum current from any one 12-volt rail of a multiple-rail PSU is limited to 20 amps (240VA / 12 volts = 20 amps), PCs with high-performance components that draw over 20 amps from the same rail are subject to over-current shutdowns. With power requirements for multiple processors and graphics cards continuing to grow, the multiple-rail design, with its 240VA limit per rail, is basically obsolete.

PC Power and Cooling is once again leading the industry. All of our power supplies now feature a large, single 12-volt rail. The design is favored by major processor and graphics companies, complies with EPS12V specs (the 240VA limit is not a requirement) and is approved by all major safety agencies such as UL and TUV.3

Should answer most of what you ment?
The last part is just advertising for PC P & C, but, hey, why not, they uber power supplies anyways.

Ste is offline  
Old 02-06-2008, 07:46 PM   #3 (permalink)
Junior Techie
Join Date: Jul 2006
Posts: 40
Default Re: PSU Rails 1,2,3 ???

Thanks for the link Ste, it reminded me of Mythbusters. lol
Antec P180
-Asus Maximus Formula X38 Mobo
-Intel E2180 (2.0) @2.81
-8800gs 384mb
-2g Corsair XMS2 DDR2 800
-Silencer 610W
-Samsung SATA DVD drive.
-Seagate 7200 rpm 300gb HDD
the_tai is offline  
Old 02-07-2008, 04:41 AM   #4 (permalink)
Newb Techie
Join Date: Feb 2008
Location: S. Central Mich.
Posts: 5
Default Re: PSU Rails 1,2,3 ???

Awesome answer. I now know what I'm gettin.
dalejiw25 is offline  
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Question regarding mini ITX and recommended PSU 96300NAZ New Systems | Building and Buying 0 12-16-2007 09:29 PM
Psu Redmo0n System Upgrades 6 12-15-2007 10:35 PM
In Depth PSU Guide: Please Read. Oreo New Systems | Building and Buying 18 10-13-2007 10:54 AM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 12:00 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.