Go Back   Hardware Canucks > HARDWARE > Power Supplies

    
Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old August 6, 2011, 12:59 PM
Prolab's Avatar
MVP
F@H
 
Join Date: Jul 2010
Location: Mississauga
Posts: 485

My System Specs

Default Low 12V rail on Corsair AX1200

Is it normal to have your 12V rail lower than 11.58 volts?

I just noticed it now when i was looking at HWMonitor. When i had my XFX BE 850, i dont remember seeing the +12V rail that low. Even when using prime95 or MSI Kombustor to simulate load - the value keeps going lower actually. Is that normal?

I thought it would be closer to 11.8+ or at least as close to 12V.

Here's a screenshot (you can zoom in if need be):

__________________
Gaming Rig:
-Swiffy MCP35x X2, (2) Aphacool UT60 480 rad, Heatkiller rev. 3.0, i7 3930k @ 4.6 Ghz, 16 GB G.SKILL F3, Asus Rampage IV Extreme, XFX R9 290 w/ XPSC WB, Crucial M4 128GB & 240 GB Intel 530, (5) 3 TB Toshiba Drive, Corsair AX1200, Win 7 Ult 64-bit

HTPC Rig:
-G3258 @ Stock, Asrock Z97 Pro 4, Gigabyte 270x, 500 GB WD Black, (5) 2 TB WD Green, (1) 3 TB Toshiba HD, (1) 2 TB Samsung F4, Fractal Design R3, Corsair HX620 PS, Win 7 Ult 64-bit
Reply With Quote
  #2 (permalink)  
Old August 6, 2011, 01:02 PM
SKYMTL's Avatar
HardwareCanuck Review Editor
 
Join Date: Feb 2007
Location: Montreal
Posts: 11,669
Default

HWMonitor isn't accurate in the least.
__________________
Reply With Quote
  #3 (permalink)  
Old August 6, 2011, 01:31 PM
Banned
F@H
 
Join Date: Aug 2007
Location: mtl
Posts: 12,694
Default

break out your multi and see what gives.

i wouldnt worry about software/sensors buggered up.

i have the little brother of the 1200 here on an asus board and it tells me 5v on the 12 lol. yes,in bios too...
Reply With Quote
  #4 (permalink)  
Old August 6, 2011, 01:46 PM
Hall Of Fame
F@H
 
Join Date: Nov 2008
Location: Ottawa, ON
Posts: 1,226

My System Specs

Default

Quote:
Originally Posted by SKYMTL View Post
HWMonitor isn't accurate in the least.
+1 don't trust those software-based voltage readings. OCCT told me my parents' computer had 4.5V on the 5.0 line, but my Agilent multimeter told me otherwise. For that matter, if you really want to diagnose a PSU, use an oscilloscope (available for the price of a GPU on robotics hobby web sites).

There's a reason why I (and I hope a lot more others) ignore any power supply reviews that use software or multimeters for their voltage readings.

EDIT: close up a loophole in last sentence ;)
__________________
"The computer programmer says they should drive the car around the block and see if the tire fixes itself." [src]
Reply With Quote
  #5 (permalink)  
Old August 6, 2011, 01:48 PM
Banned
F@H
 
Join Date: Aug 2007
Location: mtl
Posts: 12,694
Default

hey whats wrong with mutimiters lol?

better than software readings any day! :)
Reply With Quote
  #6 (permalink)  
Old August 6, 2011, 04:07 PM
Hall Of Fame
F@H
 
Join Date: Nov 2008
Location: Ottawa, ON
Posts: 1,226

My System Specs

Default

I'll admit a multimeter's better than using software - at least (if your multimeter is working and used properly) won't tell you that your +12V is giving less than 8V hehe. [see attached picture if I don't delete it for fun]

Multimeters can't detect the very high frequency ripple which can also damage hardware. If your PSU is sending small spikes or lots of ripples that are milliseconds in length to your hardware, the multimeter won't see it unless your lucky but your hardware may still take damage. Unless your multimeter is tuned for high frequency for some reason, it will just average out the reading and tell you that your +12V line is outputting 12.06V even if it's bouncing quickly between 11 and 13V or something.

See your favourite cheap exploding PSU review by Hardware Secrets / JohnnyGuru for details, like this one:
Example: Diablotek RPM-1050 1050W Review
In the review it looks like for them the multimeter (or scope taking the average like a multimeter does) shows "meh" voltages, but the ripple, which most DMMs won't see, increases as load increases.
Attached Images
 
__________________
"The computer programmer says they should drive the car around the block and see if the tire fixes itself." [src]

Last edited by frontier204; August 7, 2011 at 05:18 AM. Reason: missing words in prepositional phrase...
Reply With Quote
  #7 (permalink)  
Old August 6, 2011, 06:58 PM
Prolab's Avatar
MVP
F@H
 
Join Date: Jul 2010
Location: Mississauga
Posts: 485

My System Specs

Default

Gotcha, took out my DMM and checked BIOS... +12V is around 11.93. Thanks guys!
__________________
Gaming Rig:
-Swiffy MCP35x X2, (2) Aphacool UT60 480 rad, Heatkiller rev. 3.0, i7 3930k @ 4.6 Ghz, 16 GB G.SKILL F3, Asus Rampage IV Extreme, XFX R9 290 w/ XPSC WB, Crucial M4 128GB & 240 GB Intel 530, (5) 3 TB Toshiba Drive, Corsair AX1200, Win 7 Ult 64-bit

HTPC Rig:
-G3258 @ Stock, Asrock Z97 Pro 4, Gigabyte 270x, 500 GB WD Black, (5) 2 TB WD Green, (1) 3 TB Toshiba HD, (1) 2 TB Samsung F4, Fractal Design R3, Corsair HX620 PS, Win 7 Ult 64-bit
Reply With Quote
Reply


Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Corsair Launches Low Voltage 2133MHz DDR3 DIMMs FiXT Press Releases & Tech News 7 December 14, 2010 06:46 PM
Single vs. Multiple +12V rails: The splitting of the +12V rail yamawho Power Supplies 4 October 26, 2008 02:49 PM
PC Power & Cooling Silencer 750W Black, 60A 12V Rail, Quad PCIE SLI renoracer Buy/Sell & Trade 18 September 18, 2008 04:52 PM
Single vs Multi rail PSU's durdy Power Supplies 1 December 30, 2007 08:16 AM
-12v Rail and Poor Performance kcksteve Troubleshooting 11 September 9, 2007 08:08 PM