ATX voltage tolerances

silkstone · Apr 3, 2014

Hi guys,

I'm running extenders from my power supply to my Mobo and Video card. I'm a little concerned about the voltage drops I am seeing. When i put my cpu at load i'm getting 11.46v on the +12v line and 11.6v on the video cards 12v line.

These are (just) within the +/- 5% specs of atx, but not by much. Should I be worried at all?

shovenose · Apr 3, 2014

I wouldn't worry about it. Your hard drive is going to be the most sensitive to this kind of stuff.

rtwjunkie · Apr 3, 2014

It's relatively common to see some variance in the voltages either higher or lower, within a few percentage points. Usually becomes more common the older a PSU gets. But if things are operating fine, those variances of yours don't bother me.

Aquinus · Apr 3, 2014

It's an issue if it's because your PSU is aging or struggling. Using a thicker gauge wire for the extender would minimize resistance and voltage drop.

Are you using a multimeter to check the voltage? Onboard sensors don't always produce accurate results.

silkstone · Apr 4, 2014

Aquinus said:
It's an issue if it's because your PSU is aging or struggling. Using a thicker gauge wire for the extender would minimize resistance and voltage drop.

Are you using a multimeter to check the voltage? Onboard sensors don't always produce accurate results.

Just the on-board sensors, I don't have a digital MM and I'm not sure I could safely measure the voltages at the same time as stress testing the CPU. I know they are not 100% accurate, I may have to see what voltages get without the extenders, It just means I'll have to do my cable management all over again

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Processor	i7 8700K (@4.8 Ghz All-Core) / R7 5900X
Motherboard	Z370 Aorus Ultra Gaming / MSI B450 Mortar Max
Cooling	CM ML360 / CM ML240L
Memory	16Gb Hynix @3200 MHz / 16Gb Hynix @3000Mhz
Video Card(s)	Zotac 3080 / Colorful 1060
Storage	750G MX300 + 2x500G NVMe / 40Tb Reds + 1Tb WD Blue NVMe
Display(s)	LG 27GN800-B 27'' 2K 144Hz / Sony TV
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Audio Device(s)	On Board Realtek
Power Supply	Super Flower Leadex III Gold 750W / Andyson TX-700 Platinum
Mouse	Logitech G502 Hero / K400+
Keyboard	Wooting Two / K400+
Software	Windows 10 x64
Benchmark Scores	Cinebench R15 = 1542 3D Mark Timespy = 9758

ATX voltage tolerances

silkstone

shovenose

rtwjunkie

PC Gaming Enthusiast

Aquinus

Resident Wat-man

silkstone