Astro
sensei
- 20 јуни 2012
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Сакав да пишам дека 11,5 волти на 12 волтната линија е сеуште во ATX спецификациите. Го прашав Копиљот и еве што вика:
Here’s the short, practical answer: Most PC components expect the 12‑volt rail to stay within about ±5% of 12 V, and instability typically begins once the rail drops below roughly 11.4–11.6 V. This isn’t a hard cutoff, but it’s where real‑world problems start showing up.
What the evidence shows
Across multiple technical discussions and PSU experts:
When instability becomes likely
Based on the above:
Below ~11.7 V
Below ~11.5–11.6 V
Below ~11.4 V
Why low voltage causes instability
Bottom line
A PC typically becomes unstable when the 12 V rail drops below about 11.5 V, and anything under 11.4 V is officially out of spec and very likely to cause problems.
If you’re seeing dips below that, it’s worth investigating the PSU, cabling, or load.
Here’s the short, practical answer: Most PC components expect the 12‑volt rail to stay within about ±5% of 12 V, and instability typically begins once the rail drops below roughly 11.4–11.6 V. This isn’t a hard cutoff, but it’s where real‑world problems start showing up.
What the evidence shows
Across multiple technical discussions and PSU experts:
- A well‑regulated PSU “must be within 10%, preferably within 5%” of 12 V — meaning 11.7–12.3 V is ideal. Going outside this range can affect hard drives and VRMs.
- Users commonly report readings around 11.5–11.6 V as still “within spec,” but dipping lower raises concern.
- Many PSUs and motherboards will trigger warnings or shutdowns when the 12 V rail drops too far below spec.
When instability becomes likelyBased on the above:
Below ~11.7 V
- Not ideal, but usually still stable.
- Minor fluctuations here are common and often harmless.
Below ~11.5–11.6 V
- This is where instability becomes more likely.
- VRMs may struggle to maintain stable CPU/GPU power.
- Hard drives (especially older spinning drives) may misbehave.
Below ~11.4 V
- This is outside ATX spec.
- System crashes, reboots, or power‑surge warnings become common.
- PSU may be failing or overloaded.
Why low voltage causes instability
- VRMs (which convert 12 V to CPU/GPU voltages) are designed around a stable 12 V input. Too low, and they can’t regulate properly.
- Hard drives rely on 12 V for motor speed; low voltage can cause read/write errors.
- GPUs draw heavily from 12 V; dips can cause driver crashes or black screens.
Bottom line
A PC typically becomes unstable when the 12 V rail drops below about 11.5 V, and anything under 11.4 V is officially out of spec and very likely to cause problems.
If you’re seeing dips below that, it’s worth investigating the PSU, cabling, or load.
