Power Supply Why use an external PSU?

Arboreal

King of Cable Management
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Oct 11, 2015
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This is a really interesting thread. I am definitely in the "prefer PSU to be internal" camp.
I do see how a PSU in another pocket or away from the PC could work well; my wife has bricks at home and work for her laptop, saving a bit of weight and hassle.
I always felt that external bricks couldn't be as good as traditional PSUs as they were so cramped and not ventilated; maybe I'm wrong and doing them an injustice.
Certainly, the arguments for are more convincing than I've ever seen previously.
 

zovc

King of Cable Management
Jan 5, 2017
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I agree, it's really cool to learn about why people prefer what they do and this thread has remained really constructive.
 

Josh | NFC

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As I stated before, I use the right tool for the job, whether that be internal or external, but I wanted to give two more real world reasons I didn't see in this thread on why I like power bricks.

1. I prefer to game (when I can) on the couch. I used to have two offices in two states. I can and do store most of my stuff on network drives, but it is nice to simply move my MINI and use multiple bricks and not worry about taking a brick on the plane.

2. When I was doing installs for large organizations it was amazing to use external power bricks. As most IT people know, the PSU is the most likely culprit in a failing/failed system. Just about anyone can replace a power brick, but it would require a technician on site to replace a faulty PSU.
 

EdZ

Virtual Realist
May 11, 2015
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Just about anyone can replace a power brick, but it would require a technician on site to replace a faulty PSU.
I'd love for SFF PSUs to be available in a rear-insertable form factor, for ease of use and to make cable management easier, but that's the sort of custom design you can't feasibly do outside of high-volume (or obscenely high-margin) products.
 

robbee

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Sep 24, 2016
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I'd love for SFF PSUs to be available in a rear-insertable form factor, for ease of use and to make cable management easier, but that's the sort of custom design you can't feasibly do outside of high-volume (or obscenely high-margin) products.

There's so much server-oriented technology that would benefit the consumer market, but we're stuck with 1000 cables, heatsinks the size of houses and flashing rainbow leds :(
 

JosephEK

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Mar 6, 2017
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One question I got is about efficiency. I know standard PSU are usually rated something like bronze, silver, gold, platinum and titanium, but are power bricks more efficient than any of them?
 

robbee

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One question I got is about efficiency. I know standard PSU are usually rated something like bronze, silver, gold, platinum and titanium, but are power bricks more efficient than any of them?

External adapters work with Efficiency Levels. I think they're mainly focussed on efficiency at no and low power usage though. The requirement for the highest level (level VI) aren't anywhere near the efficiency required for Platinum or Titanium ATX specs.

More info here: http://www.fortecag.de/fileadmin/us.../Power/SL_Power/SLPE_EPS_Efficiency_Paper.pdf

PS: silver is no longer a part of the ATX efficiency specs ;-)
 
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Thehack

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External adapters work with Efficiency Levels. I think they're mainly focussed on efficiency at no and low power usage though. The requirement for the highest level (level VI) aren't anywhere near the efficiency required for Platinum or Titanium ATX specs.

More info here: http://www.fortecag.de/fileadmin/us.../Power/SL_Power/SLPE_EPS_Efficiency_Paper.pdf

PS: silver is no longer a part of the ATX efficiency specs ;-)

While you are right about the requirements aren't as stringent, a Meanwell desktop external adapter would be rated Gold if compared to ATX power supplies. It is off the mark for platinum rating because at 20% load it is only 88% efficient vs required 90%. I also hear nicer dell bricks are 90-92% efficient.

You can get high quality external AC adapters, it's just that people look at a brick and they don't want to pay $80+ for it. This is because the value proposition vs an $80 ATX PSU, the AC adapter seems like a rip-off compared to a similarly priced Gold ATX PSU that can produce 500W.
 

Ceros_X

King of Cable Management
Mar 8, 2016
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One question I got is about efficiency. I know standard PSU are usually rated something like bronze, silver, gold, platinum and titanium, but are power bricks more efficient than any of them?

Some power bricks (especially 19V) can be pretty efficent. Check this article for some testing of 19V and 12v bricks with different Pico-sized units. The available DC plug in units have come a long way from when the article was posted as well.
 

Stevo_

Master of Cramming
Jul 2, 2015
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As I stated before, I use the right tool for the job, whether that be internal or external, but I wanted to give two more real world reasons I didn't see in this thread on why I like power bricks.

1. I prefer to game (when I can) on the couch. I used to have two offices in two states. I can and do store most of my stuff on network drives, but it is nice to simply move my MINI and use multiple bricks and not worry about taking a brick on the plane.

2. When I was doing installs for large organizations it was amazing to use external power bricks. As most IT people know, the PSU is the most likely culprit in a failing/failed system. Just about anyone can replace a power brick, but it would require a technician on site to replace a faulty PSU.

Both reasons with variations I like bricks. Can take my work laptop home and just plugin. Only issues I've ever had with PCs has been PSUs, if fact the PSU in my Dell Dim 510 led me to the SFF forums, with a detour to the Fractal 304(original Enermax ATX for that was tango uniform -DOA), then the brick path L1 -> L2 -> S4.
 
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JosephEK

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Original poster
Mar 6, 2017
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What are those external PSUs that have the internal board fixed to the 24 pin motherboard power plug? That's something I'd be really interested in learning about.

I think it would be ideal for a sort of DIY barebone build.
https://images-na.ssl-images-amazon.com/images/I/41sZ4YdlgCL.jpg
One of these things. But maybe a bit more than 160W would be nice.

The only wires I would need for such a build would be motherboard and CPU power I think because I could use M.2 storage and integrated or low profile GPU.
 
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Stevo_

Master of Cramming
Jul 2, 2015
449
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What are those external PSUs that have the internal board fixed to the 24 pin motherboard power plug? That's something I'd be really interested in learning about.

I think it would be ideal for a sort of DIY barebone build.
https://images-na.ssl-images-amazon.com/images/I/41sZ4YdlgCL.jpg
One of these things. But maybe a bit more than 160W would be nice.

The only wires I would need for such a build would be motherboard and CPU power I think because I could use M.2 storage and integrated or low profile GPU.

The HD-Plex version can drive more especially if you have a fan on it.

http://www.hd-plex.com/HDPLEX-160W-DC-ATX-Power-Supply-16V-24V-Wide-Range-Voltage-Input.html
 

Grafite

3D Printing Enthusiast
Feb 20, 2017
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You can get high quality external AC adapters, it's just that people look at a brick and they don't want to pay $80+ for it. This is because the value proposition vs an $80 ATX PSU, the AC adapter seems like a rip-off compared to a similarly priced Gold ATX PSU that can produce 500W.

This is my only gripe with external bricks. The costs are almost twice as much as a high-quality PSU. A HDPlex 300w is $80-$100 and the brick is also $80-$100. For that price I can buy a Corsair SFX 450w Modular PSU and pay for a kit to make custom cables. But then again that is the price of Ultra SFF.
 

aquelito

King of Cable Management
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Feb 16, 2016
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I cherish silence above all. That's why I tend to favor DC boards with AC adapters.

- Fanless combo
- Fewer "hot" components in a small case => less heat released and more volume to breath => slower fans
 
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JosephEK

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Mar 6, 2017
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It seems the best of these Pico PSUs I can find is 160W. Would this be enough for a 65W TDP APU with say 8GB of DDR4 and an M.2 SSD? If so I could make a budget build that's almost as small as the power brick itself lol. That is ofcourse one Ryzen APUs are out. I hope they have that onboard VRAM I heard rumors about.

Uh one ,ore question is:
Is there any difference for life span for external PSU compared to an internal one? Do they die any sooner or later?
 

Thehack

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It seems the best of these Pico PSUs I can find is 160W. Would this be enough for a 65W TDP APU with say 8GB of DDR4 and an M.2 SSD? If so I could make a budget build that's almost as small as the power brick itself lol. That is ofcourse one Ryzen APUs are out. I hope they have that onboard VRAM I heard rumors about.

Uh one ,ore question is:
Is there any difference for life span for external PSU compared to an internal one? Do they die any sooner or later?

I mean 160 is bigger than 65 so yeah it'd work.

It depends on the PSU you get. Usually in a PSU it's the capacitors that fail. The majority of them should last for the lifetime of the build you make. The spec you want is mean time between failure which is hard to have. A meanwell industrial external adapter is rated at about 209k hours.
 

JosephEK

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I mean 160 is bigger than 65 so yeah it'd work.

It depends on the PSU you get. Usually in a PSU it's the capacitors that fail. The majority of them should last for the lifetime of the build you make. The spec you want is mean time between failure which is hard to have. A meanwell industrial external adapter is rated at about 209k hours.
Yeah, but 65W is only the TDP, IDK how many watts a 65W TDP chip actually uses.
 

jeshikat

Jessica. Wayward SFF.n Founder
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Feb 22, 2015
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It's not exact, but Intel's TDP figures are roughly how much power the chip consumes. TDP is how much heat system designers should expect to deal with, but CPUs (and GPUs, and really any processor) don't do mechanical work so all the power consumed gets converted to heat.

Intel and AMD measure differently though so they can't really be compared, like the 95W Ryzen 1800X may average around 95W thermal output, but it can spike in power to levels comparable to the 140W TDP Intel X99 CPUs.
 

Thehack

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Yeah, but 65W is only the TDP, IDK how many watts a 65W TDP chip actually uses.

And if you're really interested, just check any reviews for power consumption to give you the ballpark. Keep in mind reviews are generally worst case scenario power consumption. It's like you're running Prime95 or AIDA when you game or watch netflix.