Aceptable PSU voltage fluxuation??

[DUSNOETOS]

I am trying to determine if some old PSU's I have are still OK and safe to use.
based on this chart I found the PSU's in question still fall with in spec.

73954

Is this information safe to trust??? I expect some small variances based on load but nearly one whole volt seems a bit much. If this chart is not reliable what is acceptable variances

[burebista]

Is written in ATX12V v2.x standard:±5%.

[DUSNOETOS]

Is written in ATX12V v2.x standard:±5%.

sure... but is that a reliable standard to follow. A one volt fluctuation makes me nervous...

[burebista]

Agree, but this is the standard. :)
If you want a 1-2% regulation you can choose a top notch PSU. ;)

[RollingThunder]

sure... but is that a reliable standard to follow. A one volt fluctuation makes me nervous...

Dusnoetos,

Agree with Burebista. The best power supplies will read within .1v or .2v of default factory readings or better using a DMM on all rails and remain steady under load, particularly the 12v. rails

12.0v default = 11.80 to 12.20v via DMM

As an example, I run two Corsair HX520's and they both are nearly 1% of that standard. Many other good power supplies will do the same. While the 5% is the accepted standard, and as Burebista stated, top notch power supplies will cut that 5% standard in half easily. You normally get what you pay for.

[DUSNOETOS]

So... my old Antec smartpower 400 watt PSU that drops to 11.97-11.96 volt under the load of 4 fans should not worry me.??

[RollingThunder]

So... my old Antec smartpower 400 watt PSU that drops to 11.97-11.96 volt under the load of 4 fans should not worry me.??

That's not a valid test of a power supply assuming they are 12v computer fans. What's your default base-line, no-load reading using a DMM? Your DMM shouldn't budge with that load.