Silent high efficiency ~100W PSU?

[fjodor2000]

Hi,

I'm looking for a silent high efficiency PSU. It'll be powering an Intel Atom D510 / 2 GB RAM and 2 x 2 TB low power HDs. Most of the PSUs I can find are rated at 300-400W or above, which seem like waste in my case, since I expect my system to not consume more than 20-30 W!

So now I just wonder what recommendations you have?

Thanks!

[Jay_S]

It'll be powering an Intel Atom D510 / 2 GB RAM and 2 x 2 TB low power HDs. ... [snip] ... I expect my system to not consume more than 20-30 W!

Those 2TB drives are going to require a bunch more current during spin-up than while idling at 30W. Spin-up current draw from 2 common 2TB drives:
Western Digital WD20EADS / WD20EARS: 1.7A @ 12V = 20.4W
Hitachi 7K2000: 2.0A @ 12V = 24W

So you're looking at potentially 50W during spin-up of two drives. The D510MO requires very little. You could probably get by with the PicoPSU 120 + 80W brick.

The problem with the PicoPSU's is that you have no room to grow. Though, the D510MO's 2 sata ports limit you anyway.

[fjodor2000]

I've actually measured the total power consumption of the system (using a Voltcraft Energy Logger 4000), and with only one 2TB drive it is ~30-35W when idle (and ~45W at max, including startup). However, this is with a standard low efficiency PSU, so with a high efficiency PSU the power consumption will likely be lower.

Anyway, I've thought about using a PicoPSU, but I have some concerns:

* The PicoPSU has no fan. Since there will be no other fan in the computer case either, won't there be a risk of over-heating? However, all parts are very low power in my case, and the case has "air vent holes" on three sides (see http://www.morex.com.tw/products/imgproduct/127-1.jpg), so maybe that will be enough?

* Is there a way to mount the PicoPSU + Power Brick in the same location as the standard ATX PSU? I.e. I want to remove the existing PSU and replace it with a PicoPSU + Power Brick. I guess what I'm looking for is some kind of "ATX PSU sized" mounting frame for the PicoPSU + Power Brick.

[MtnHermit]

Don't make the mistake of getting an unrated smaller PSU, from my tests they're all junk.

Code: Select all

      PSU          FF       No Load      Idle     Comments
Seasonic 180W     SFX        7W           44W     SS-180SFD  
Sparkle 200W      SFX        9W           45W     FSP200-50SNV
Antec EW 380W     ATX        6W           34W     EA-380 80+
TT 420W           ATX       14W           45W     Thermaltake HPC-420-102DF
Bestec 250W       ATX        6W           39W     ATX-250-12Z Compaq OEM

All the PSU's were connected to a i3-530 on a Gigabyte microATX MB w/4GB DDR3 and a notebook HDD.

No load is simply shorting the green to any black, nothing connected. Not a meaningful PC test, but of interest for its own sake.

I have a Dell RM112 (235W, 80+ Silver) all soldered up and ready to test, it should handily beat all the above. Theirs a thread here where a user modified a ATX PSU case with a Dell RM112 inside. How handy are you?

[fjodor2000]

Thanks for your reply MtnHermit.

I'm not sure I follow you though. Do you consider all the PSUs you listed to be junk? If so, what would be an acceptable result.

Also I'm not sure what you are suggesting with what you wrote in the last paragraph? Are you suggesting that I should buy a Dell RM112 and modify it somehow? If so, would that be a better option than buying a PicoPSU + Power Brick?

[Jay_S]

...this is with a standard low efficiency PSU, so with a high efficiency PSU the power consumption will likely be lower.

Efficiency will only get you so far - you need to "fit" the system with the PSU to make sure it's running at within it's most efficient range. For example, 80+ cert means 80% or more efficient from 20% rated power to 80% rated power. For the Antec EW 380, this means it's 80% efficient between 76W - 304W. Your system will be under this range most of the time. But, as MtnHermit's data shows (great data BTW!), going with a lower power PSU isn't always the most efficient solution. I have the Antec EW380 in my HTPC. It's been rock solid. It replaced the non-80+ Antec 380W PSU that came in my NSK2400 case - yay 3-year warranty.

I also own a D510MO. You can see my build here. Prior to purchasing the PicoPSU I was using an old Zalman 300W ATX PSU. With a 2.5" notebook drive and a 80mm 0.09A fan my Kill-a-Watt read 32W idle. With the PicoPSU & 60W brick it dropped to 15W idle.

The PicoPSU has no fan. Since there will be no other fan in the computer case either, won't there be a risk of over-heating?

Maybe, but I'm not sure that the PSU fan would be all the much help. I just dug an old 80mm fan from my spares bin. I have the MB fan control disabled, and the fan is fixed at 50%. I can't hear it and my CPU temps are always really low. What HDD's are you using? Depending on your level of HDD activity, they may need more air than the D510MO.

Is there a way to mount the PicoPSU + Power Brick in the same location as the standard ATX PSU?

I suppose this will depend on the size of the brick you buy. My 60W brick is really small.

[MtnHermit]

Thanks for your reply MtnHermit.

I'm not sure I follow you though. Do you consider all the PSUs you listed to be junk? If so, what would be an acceptable result.

Also I'm not sure what you are suggesting with what you wrote in the last paragraph? Are you suggesting that I should buy a Dell RM112 and modify it somehow? If so, would that be a better option than buying a PicoPSU + Power Brick?

The table is pretty self explanatory. Note the 380W 80+ Earthwatts easily beats all those smaller unrated PSU's. If it doesn't say 80+ on the label, take a pass.

The Dell is a soldering nightmare and a non-standard size, but if you have the skills and time it'll beat a PicoPSU + brick. Read the thread in this forum, photos and tests. They're cheap too, ~$35.

[MtnHermit]

I was using an old Zalman 300W ATX PSU. With a 2.5" notebook drive and a 80mm 0.09A fan my Kill-a-Watt read 32W idle. With the PicoPSU & 60W brick it dropped to 15W idle.

I'll bet that Zalman took at least 10W just to run itself. Quick test to find out (green to black). But 15W is impressive.

[gabeyd]

I'm using a Pico 150W in my D510MO build with an 80W adapter that came with the Pico in a retail kit at Fry's.

Details, photos, and power consumption data for my build here:

viewtopic.php?t=57965

[bean1975]

viewtopic.php?t=55353