Power Supply Wattage and Utilization in relation to noise (HELP!)

[Dogsuferer101]

I have never found a solid answer to this question. I am trying to get a power supply that wont spin up much or make much noise at all. I am currently looking at the Seasonic Prime 850w. I currently have a seasonic x series 1250w and it can get pretty loud. My question is... at what point do the fans spin up? Is it at a certain utilization PERCENTAGE? Or is it once everything hits (X) amount of watts. If it is based on percentage, wouldnt it make sense to have a higher wattage PSU to increase the utilization percentage, therefore the fan wouldnt spin as soon? For example If you have a 850w and a 1250 watt and the fan starts to spin at 30 percent utilization, then the higher wattage psu fan would spin up at 350w and the 850 would spin up 255w. I am totally misunderstood? I want to know if its wattage based or percentage based. Lets say that my computer takes 400w overall at load. Would having a higher wattage psu increase my changes of it being more quiet because of how much is being utilized?

 

[Barty1884]

Generally speaking, it's temperature related and not utilization/wattage (of course utilization/wattage provided etc all play a part in temperatures).

In theory, yes, a lower utilization (even at max load) should result in lower temps, but there's many variables (ambient temp, airflow in the case, top vs bottom mounted PSUs among other things).

 

[Dogsuferer101]

Generally speaking, it's temperature related and not utilization/wattage (of course utilization/wattage provided etc all play a part in temperatures).

In theory, yes, a lower utilization (even at max load) should result in lower temps, but there's many variables (ambient temp, airflow in the case, top vs bottom mounted PSUs among other things).

Where does the 80 efficiency come into play? If you have a lower wattage, more efficient psu would that be better than to have a higher wattage less efficient psu in relation to temperature and potential noise levels If the overall max load of your computer is 400 watts?

 

[Barty1884]

In the most simple of senses, the 80+ certification is the balance between what the PSU is providing to your rig & what it pulls from the wall.
As an example, system needs 400W at load - at 80% efficiency it's pulling 500W from the wall (with 400W being 80% of 500W) - but that's a little too simplistic. PSUs are X efficient depending on it's load and classification (Bronze through Titanium), at minimum there's all 80% efficient, but some (Titanium) can operate up to 96% efficiency (with a PSU at 50% load)

Again, it depends on the PSU. The theoretical ideal (to keep temps low) would be a higher wattage capability and more efficient PSU - but a high wattage, Titanium PSU is overkill for 99.9% of users.

If I were you, I'd look for a quality PSU (check here: http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html) and the largest fan available in a PSU. A larger fan can move more air - will be quieter, and will cool faster (generally). Therefor, if/when your PSU fan does need to kick in, it would likely only be for short bursts, and would be quieter.

 

[Dogsuferer101]

In the most simple of senses, the 80+ certification is the balance between what the PSU is providing to your rig & what it pulls from the wall.
As an example, system needs 400W at load - at 80% efficiency it's pulling 500W from the wall (with 400W being 80% of 500W) - but that's a little too simplistic. PSUs are X efficient depending on it's load and classification (Bronze through Titanium), at minimum there's all 80% efficient, but some (Titanium) can operate up to 96% efficiency (with a PSU at 50% load)

Again, it depends on the PSU. The theoretical ideal (to keep temps low) would be a higher wattage capability and more efficient PSU - but a high wattage, Titanium PSU is overkill for 99.9% of users.

If I were you, I'd look for a quality PSU (check here: http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html) and the largest fan available in a PSU. A larger fan can move more air - will be quieter, and will cool faster (generally). Therefor, if/when your PSU fan does need to kick in, it would likely only be for short bursts, and would be quieter.

Thanks bud

 

[thx1138v2]

It's an interesting question but you are not looking at enough parameters. Given your example, one of the determining factors would be efficiency. When two PSU's of the same wattage have different efficiencies one will produce less heat and the other more heat.

But that's only one factor. How well the heat is handled also plays a role. A less efficient PSU generating more heat, relatively speaking, could fare better if more of its heat is removed than in the higher efficiency unit.

So to make your comparison work you have to state that the PSUs being compared had the same efficiency and the same heat removal capabilities and are operating in the same environment. But you'll never find that in the real world in the case of PSU's with differing wattages because the units being compared will be built using different components in different arrangements within different enclosures and therefore different airflow to remove the heat.

Maybe a PSU engineer could find some basis for comparison but it would be far more complicated than what your question is asking.

 

[Dogsuferer101]

It's an interesting question but you are not looking at enough parameters. Given your example, one of the determining factors would be efficiency. When two PSU's of the same wattage have different efficiencies one will produce less heat and the other more heat.

But that's only one factor. How well the heat is handled also plays a role. A less efficient PSU generating more heat, relatively speaking, could fare better if more of its heat is removed than in the higher efficiency unit.

So to make your comparison work you have to state that the PSUs being compared had the same efficiency and the same heat removal capabilities and are operating in the same environment. But you'll never find that in the real world in the case of PSU's with differing wattages because the units being compared will be built using different components in different arrangements within different enclosures and therefore different airflow to remove the heat.

Maybe a PSU engineer could find some basis for comparison but it would be far more complicated than what your question is asking.

Thanks dude!

 

[Barty1884]

Agree on most points there ^^

That's why I used a healthy spattering of 'generally', 'depends' & 'theory' etc. Waay too simplistic to answer definitively.