which is more dangerous for PC on 12V rail : 11.5V or 12.5V ?? - Page 2 - Overclock.net - An Overclocking Community

Forum Jump: 

which is more dangerous for PC on 12V rail : 11.5V or 12.5V ??

Reply
 
Thread Tools
post #11 of 24 (permalink) Old 12-23-2018, 09:01 PM
Overclocker
 
JackCY's Avatar
 
Join Date: Jun 2014
Posts: 9,990
Rep: 339 (Unique: 240)
Yes, feeding VRMs lower voltage will cause higher current draw.
Feeding a resistor lower voltage will cause lower current draw.
JackCY is offline  
Sponsored Links
Advertisement
 
post #12 of 24 (permalink) Old 12-23-2018, 09:09 PM
Mr.4way SLI
 
Moparman's Avatar
 
Join Date: Jun 2009
Location: Farmington MO
Posts: 5,418
Rep: 191 (Unique: 171)
Moparman is offline  
post #13 of 24 (permalink) Old 12-24-2018, 11:22 AM
Optimal Pessimist
 
GeneO's Avatar
 
Join Date: Jan 2011
Posts: 2,296
Rep: 114 (Unique: 87)
Quote: Originally Posted by white owl View Post
If you feed something less voltage and it's able to have the same output with said voltage, ohms law says it must be pulling more current to make up the difference. I'm not sure it this applies to the PC or not since the components do not feed directly from the PSU, the power is stepped up and down. I'm not sure what it's called but there are little chips that can regulate output and keep it the same even if the input voltage drops, this will cause it to draw more current. If the VRM is fed by something like this I don't think too little voltage will harm the CPU or VRM as it will be getting the same power either way but I'm not a rocket doctor and I don't know exactly how much bucking/stepping and filtering the 12v power goes through before reaching the VRM.

That isn't ohms law. Ohms law is the voltage is proportional to the current, so you lower voltage you lower current.

FDR4-8086k
(22 items)
CPU
8086k 5.1/4.8 GHz @ 1.296v (AVX 0, adaptive)
Motherboard
Asus Maximus X Code
GPU
Asus GTX 2070 Super A8GB
RAM
32GB g.skill Trident Z RGB @ 3733 16-16-36, 1.36v
Hard Drive
Samsung 850 EVO 1TB
Hard Drive
Western Digitial Caviar Black 2 TB in USB 3.0 enclosure
Hard Drive
Western Digital Black 6 TB
Hard Drive
Western Digitial Caviar Green in USB 3.0 enclosure
Hard Drive
Samsung 960 Pro 512 GB
Hard Drive
Samsung 860 EVO 1TB
Power Supply
Seasonic Prime Ultra Titanium 750W
Cooling
Noctua NH-D15 (only middle NF-A15 Chromax)
Cooling
4 x Noctua NF-A14 Chromax black swap
Cooling
Noctua NF-F12 Chromax black swap
Case
Fractal Design R4
Operating System
Windows 10 Pro 64 bit
Monitor
Eizo CG2730
Monitor
DELL P2217H
Keyboard
Cooler Master Quickfire Rapid TKL
Mouse
Logitech G305
Mouse
perixx dx-2000
Audio
On Board SupremeFX
▲ hide details ▲
GeneO is offline  
Sponsored Links
Advertisement
 
post #14 of 24 (permalink) Old 12-24-2018, 11:29 AM
Head Dwarf
 
iamjanco's Avatar
 
Join Date: Aug 2016
Location: In a circus tent
Posts: 1,990
Rep: 93 (Unique: 57)
Quote: Originally Posted by GeneO View Post
That isn't ohms law. Ohms law is the voltage is proportional to the current, so you lower voltage you lower current.
That is partially correct, but I suspect you know that. For those who'd like additional info, see: Ohms Law and Power

Excerpt:

Quote:
Georg Ohm found that, at a constant temperature, the electrical current flowing through a fixed linear resistance is directly proportional to the voltage applied across it, and also inversely proportional to the resistance.

Muffler Bearings
(19 items)
CPU
SL Intel® Core™ i9-7900X
Motherboard
Asus Rampage VI Extreme
Motherboard
EVGA X299 DARK
GPU
EVGA GeForce RTX 2080 Ti XC
GPU
(2 ea) EVGA GTX 1080 Ti FTW3
RAM
G.SKILL F4-3200C14Q2-64GTZ
Hard Drive
(2ea) Intel Optane 900P (480GB)
Hard Drive
(2ea) Samsung 850 Pro 1TB
Hard Drive
(2ea) Samsung 850 Pro 256GB
Hard Drive
(1ea) Samsung 970 Pro 512GB
Hard Drive
(1ea) Samsung 950 Pro 256GB
Power Supply
EVGA SuperNOVA 1600 T2
Cooling
Custom water
Case
Custom, 8020x3060 and x2020
Operating System
Win 10 Pro/Ubuntu
Monitor
NEC PA272W-BK-SV
Monitor
Eizo ColorEdge CE240W
Monitor
Alienware AW3418DW
Audio
Bottlehead Mainline Amp
▲ hide details ▲


iamjanco is offline  
post #15 of 24 (permalink) Old 12-24-2018, 12:06 PM
Optimal Pessimist
 
GeneO's Avatar
 
Join Date: Jan 2011
Posts: 2,296
Rep: 114 (Unique: 87)
I think white owl was referring to feeding the CPU a constant VRM output voltage and power. And for a lower input voltage to the VRM, more current must be supplied for it to deliver the same power. That isn't strictly ohms law is all I meant.

FDR4-8086k
(22 items)
CPU
8086k 5.1/4.8 GHz @ 1.296v (AVX 0, adaptive)
Motherboard
Asus Maximus X Code
GPU
Asus GTX 2070 Super A8GB
RAM
32GB g.skill Trident Z RGB @ 3733 16-16-36, 1.36v
Hard Drive
Samsung 850 EVO 1TB
Hard Drive
Western Digitial Caviar Black 2 TB in USB 3.0 enclosure
Hard Drive
Western Digital Black 6 TB
Hard Drive
Western Digitial Caviar Green in USB 3.0 enclosure
Hard Drive
Samsung 960 Pro 512 GB
Hard Drive
Samsung 860 EVO 1TB
Power Supply
Seasonic Prime Ultra Titanium 750W
Cooling
Noctua NH-D15 (only middle NF-A15 Chromax)
Cooling
4 x Noctua NF-A14 Chromax black swap
Cooling
Noctua NF-F12 Chromax black swap
Case
Fractal Design R4
Operating System
Windows 10 Pro 64 bit
Monitor
Eizo CG2730
Monitor
DELL P2217H
Keyboard
Cooler Master Quickfire Rapid TKL
Mouse
Logitech G305
Mouse
perixx dx-2000
Audio
On Board SupremeFX
▲ hide details ▲

Last edited by GeneO; 12-24-2018 at 12:17 PM.
GeneO is offline  
post #16 of 24 (permalink) Old 12-24-2018, 01:49 PM - Thread Starter
Not New to Overclock.net
 
pulverizor's Avatar
 
Join Date: Jun 2015
Posts: 231
Rep: 0
so everyone here agrees +0.5V is more dangerous then -0.5V for components? (+0.5V can fry components, -0.5V wont damage components but can only melt cables?)


same question for 11V vs 13V , 13V can damage CPU/GPU/mobo but 11V will only melt cables/wiring/"cheap-stuff" or something?
pulverizor is offline  
post #17 of 24 (permalink) Old 12-24-2018, 01:58 PM
Watercooled
 
lexer's Avatar
 
Join Date: Jul 2015
Location: Argentina
Posts: 865
Rep: 47 (Unique: 33)
The cases that I saw melted connector was when the output capacitors blowup and the voltage becomes very low and unstable. Not sure if was caused by the ripple or the low voltage but the CPU connector just melt and in some cases the primary capacitors of the vrm blow up. I only see this only with really cheap PSU with low end hardware.

I7 8700K@4.7Ghz / Z370-A / 2X8GB 3200Mhz ADATA Spectrix D40 / 1TB Intel 600P / EVO 850 250GB / 4TB WD Gold / RTX 2080 GAMING OC / NZXT Noctis 450 ROG / EVGA G2 850W@ECO
Heatkiller REV 3.0 / XSPC EX360 / DDC 3.25 + EK-XRES / 3x Venturi HF-12 PWM
lexer is offline  
post #18 of 24 (permalink) Old 12-24-2018, 01:58 PM
High Clocker
 
bmgjet's Avatar
 
Join Date: Nov 2011
Posts: 3,152
Rep: 188 (Unique: 162)
Quote: Originally Posted by pulverizor View Post
so everyone here agrees +0.5V is more dangerous then -0.5V for components? (+0.5V can fry components, -0.5V wont damage components but can only melt cables?)


same question for 11V vs 13V , 13V can damage CPU/GPU/mobo but 11V will only melt cables/wiring/"cheap-stuff" or something?
Id take +0.5V over -0.5v.
Id rather have higher voltage then low voltage.

If the PSU was putting out voltage outside of spec tho id return it and get a proper working one.


SLI Voodoo 2 - > GeForce4 MX 420 -> GF 6600GT -> GF 6800GT -> GF 8800Ultra -> AMD 4870 -> AMD 4890 -> CF AMD 5820 -> CF AMD 6850 -> CF AMD 7970 -> SLI GF 680 -> SLI GF 780 -> CF AMD 290X -> GF 980ti -> SLI GF 980ti -> GF 1080ti -> SLI GF 1080ti -> <- RTX 2080ti (DOA/Refunded)
CPU
AMD 8120
CPU
FX 8350
GPU
7970 CFX
GPU
680 SLI
▲ hide details ▲


bmgjet is offline  
post #19 of 24 (permalink) Old 12-24-2018, 02:12 PM
Never Finished
 
airisom2's Avatar
 
Join Date: Aug 2011
Location: Within the Milky Way
Posts: 2,063
Rep: 268 (Unique: 206)
I'd take 12.5v over 11.5v. Some units go slightly over 12v so that it can accommodate for voltage droop under load. For example, a power supply may read 12v in the bios, but under load that voltage might drop to 11.8v. So, having a slightly higher 12v will mitigate that. Running it higher also helps a bit with efficiency and is a trick you can use to get a higher 80+ cert.

Regardless, both extremes are within spec, so I would only worry about voltage regulation when it's outside of +/- 5% or if the fluctuation swings are too wide or frequent. FYI, EVGA will deem a unit defective if it fluctuates more than 0.05v (any voltage), if it fluctuates rapidly (any voltage), or if 12v is outside 11.4-12.6v.

1680 V2 4.5GHz 1.33v | G.Skill Trident X 4X4GB 2400MHz | R4BE | Titan Xp + Morpheus II
Wasabi Mango UHD550 | Rosewill Rise | Thermalright LGM RT
Logitech G600 | G440 | Tt Meka G-Unit Cherry MX Black+Double O-Rings
JBL LSR308s | Temblor T10 | Custom headphones | TEAC-UD501+Passive Preamp | Emotiva BasX A-100
OCZ Vertex 4 256GB | 51TB DAS | SS Prime Ultra Titanium 1KW
airisom2 is online now  
post #20 of 24 (permalink) Old 12-24-2018, 02:17 PM
Overclocker
 
EastCoast's Avatar
 
Join Date: Feb 2010
Posts: 3,106
Rep: 140 (Unique: 94)
Are we talking a consistent voltage or if it fluctuates between the 2?
EastCoast is offline  
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Overclock.net - An Overclocking Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may post new threads
You may 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 Off
Pingbacks are Off
Refbacks are Off