Should I buy a SeaSonic Power Supply? And which one?

[imported_smilingcrow]

Your system looks as if it?s too low power for you to save much money on switching to a more efficient P/S.
Many people focus on how efficient the P/S is at higher loads, but if your system is idling a lot then the efficiency under a low load is much more important when calculating cost savings.
Have a look at www.silentpcreview.com as they have some great articles and reviews that include looking at P/S efficiency at different load levels and they also show typical power draws for a variety of systems at idle & load.
This link http://www.silentpcreview.com/article313-page6.html includes a look at comparing typical running costs for a number of desktops systems; it?s not specifically comparing P/Ss but it gives you an idea of how to calculate your own savings.
They?ve only just reviewed the latest revision to the Seasonic S12 330W; http://www.silentpcreview.com/article596-page1.html

I have an S12 430 and I?m very happy with it; the only next step for me would be a passively cooled P/S which isn?t an issue as my system only consumes 115W A/C under full load.

 

[jonnyGURU]

Originally posted by: homestarmy

Originally posted by: MWink
I think people are blowing the whole efficiency thing way out of proportion. I've tested a number of PSU's ranging from high rated came-with-a-$25-case units, to FSP's, to Antecs, the Seasonic S12, and the PC Power and Cooling Silencer. I tested them in the same systems and measured their draw with a Kill-a-Watt.

The results showed that the difference, in draw, in watts is very small. Only about 10 watts from the best to the worst. The biggest difference was in the draw in VA. The units with active PFC's had a much lower draw in VA's. The units without PFC's could draw well over 100VA more.

This means that if you're concerned with your computer's draw in watts, a different PSU may not make much difference at all. Honestly it would NOT likely pay for itself during its useful life. If you're concerned with draw in VA then one with an active PFC would be a good idea. Just remember most people (at least in the U.S.) pay for Kilo-Watt-hours.

Thanks very much for the information!

Unfortunately, I am not sure that I understand the relationship between Volt-Amps and Watts. I thought that Volts x Amps = Watts, so they were essentially the same thing? There must be something simple that I am missing, would you or anyone care to point that out?

I am billed by Kilowatt hours btw.

If you're billed by KwH, don't sweat it so much.

(VA) = (A) * (W) / (PF)

So if you have a PSU with active PFC, and your PFC is .99, then your VA is the same as your Wattage.

If you have no PFC, then your PF is probably .60, then your VA is going to be higher than your wattage.

But like Bob said, if you're charged by KWh, then VA doesn't matter.

Oh... and also... efficiency for a PSU is a bell curve. Not a straight line and not a slope. So a PSU may be better at one particular wattage, but not at another. So you have to be careful when reading things like "efficiency > 70% at full load" and "up to 80% efficiency" on two different PSU boxes. They might actually be the same efficiency!

 

[One43637]

^^

see, you mention his name and he's bound to post

 

[homestarmy]

Originally posted by: jonnyGURU
If you're billed by KwH, don't sweat it so much.

(VA) = (A) * (W) / (PF)

So if you have a PSU with active PFC, and your PFC is .99, then your VA is the same as your Wattage.

If you have no PFC, then your PF is probably .60, then your VA is going to be higher than your wattage.

Thanks very much for the info... but what is PFC again?

Thanks!

 

[jonnyGURU]

Originally posted by: One43637

see, you mention his name and he's bound to post

That's usually how it works. Like a genie from a lamp.

Originally posted by: homestarmy

Originally posted by: jonnyGURU

If you're billed by KwH, don't sweat it so much.

(VA) = (A) * (W) / (PF)

So if you have a PSU with active PFC, and your PFC is .99, then your VA is the same as your Wattage.

If you have no PFC, then your PF is probably .60, then your VA is going to be higher than your wattage.

Thanks very much for the info... but what is PFC again?

Thanks!

Power Factor correction. Your power factor is higher the more simple your load is. A power supply has a complex load on the AC. So in few words, power factor correction (PFC) simplifies that load so the load appears more "simple" to the mains.