12v rail gets 11.56v under load with a GTX275

[ajaidevsingh]

I have a Cooler master extreme power Plus 650W SMPS and have just attached a HDD and a PCI WiFi card to it. The system has a Athlon 4400+ and a basic micro ATX m/b. I bought a GTX 275 and gave it a try even when the min was rated at 40A SMPS for the card and mine had 36A.

To take a safer route i under clocked it quite a bit and ran the system. The system worked and still is working ok but i did note when the Card and CPU is pushed to the limit while benchmarking the 12v rail goes down to 11.56v-11.59v but the card runs fine and benchmarks show no artifacts what so ever.

So my question is will 11.56v on a 12v be a problem. Since i have no stability issues and the system works fine tough the smps is a bit warmer than before??

 

[HOOfan 1]

Originally posted by: ajaidevsingh
I have a Cooler master extreme power Plus 650W SMPS and have just attached a HDD and a PCI WiFi card to it. The system has a Athlon 4400+ and a basic micro ATX m/b. I bought a GTX 275 and gave it a try even when the min was rated at 40A SMPS for the card and mine had 36A.

To take a safer route i under clocked it quite a bit and ran the system. The system worked and still is working ok but i did note when the Card and CPU is pushed to the limit while benchmarking the 12v rail goes down to 11.56v-11.59v but the card runs fine and benchmarks show no artifacts what so ever.

So my question is will 11.56v on a 12v be a problem. Since i have no stability issues and the system works fine tough the smps is a bit warmer than before??

If you didn't obtain your voltage reading with a multimeter then your numbers are useless. Software readings are useless.

 

[ajaidevsingh]

Pls see Topic Summary...

have already said that i am using a digital multimeter....

 

[HOOfan 1]

Sorry I didn't see that part.

Anyway, the voltages you obtained are within Intel's ATX specification. Many components are actually designed to work with input voltages even lower or higher than Intel's spec.

You stated in another thread, that without the underclock it doesn't work though. you may be pushing your PSU close to its limit. While you seem to be fine now, you may not be for too much longer. Stressing a PSU can shorten its life.

Is your CPU overclocked?

 

[ajaidevsingh]

No the CPU is at stock its a Athlon x2 4600+, non of the components are OCed

 

[theAnimal]

What's the idle voltage?

 

[Modelworks]

Spec is with 5% of voltage. So 12V - .6 = 11.4V or 12V + .6 = 12.6V so you are fine.
Also realize that nothing in the pc actually uses 12V. It is converted down to other voltages much lower. Even if the voltage drops to 11 volts it would still function, it would just draw more current.

 

[doubleOseven]

Fans use 12 volts...

 

[lopri]

oops. wrong thread. sorry

 

[BonzaiDuck]

Originally posted by: doubleOseven
Fans use 12 volts...

That's true, but many fan controllers perform their function by under-volting the fans. So there's no threat to the fans, and possibly only a slightly-lower top-end rpm as opposed to the fan's spec.

The OP's voltage readings are within 3.7% of the spec, which is quite acceptable. I've seen people fret when the 12V rail is just over 2% different from the spec. 2% is considered to be quite good, and the other comment about 5% is probably correct for the ATX power specification of the 12V rail.