Power Supply Favorite Internal PSU form factor?

[JosephEK]

Flex ATX,
TFX,
SFX,
ATX?,
Or maybe even that Nano-ATX thing HDPLEX makes with the 200W internal brick?
Not sure what else I'm missing. Maybe some other proprietary solutions?

What is your favorite and possibly tell what you think some of the pros and cons are of these different form factors.

 

[theGryphon]

Not used it yet, but my favorite is FlexATX. Noise concerns notwithstanding, I think it's the best form factor for SFX, enabling most design choices. Noise is not as big an issue now compared to a few years ago with higher efficiency components and increasing R&D along with popularity.
I like the idea of custom designs too (heck, I'm using one right now) but not having a "standard" is troublesome. Larger players need a standard to base designs on and I believe FlexATX is the new SFX.

 

[CountNoctua]

SFX-L. Might not be standard, but much prefer having room for a 120mm fan. Also the wattages (e.g. 800W Silverstone) and quality are getting close to meeting vast majority's needs for SFF builds.

Haven't built with smaller than SFX yet. One of these days.

 

[Necere]

SFX/SFX-L is by far the best all-round form factor currently. It has the best balance of power, noise, size and availability.

ATX is useful mainly for niche applications at this point, e.g. multi-GPU workstations where the 800 or so watts of SFX/SFX-L won't cut it. Also budget builds, I suppose.

FlexATX enables some of the most compact systems possible, with the significant caveat of a tiny, whiny 40mm fan. That, plus limited choices and availability, cost, lack of modularity and PCIe cables, give it some significant shortcomings when compared to SFX. Only useful when you really want to min-max a system.

TFX is a weird middle child that isn't really good at anything. It's as tall as SFX, as wide as FlexATX, but longer than either, which makes it less useful than it could be. Most of the time you'd be better off with one of the other form-factors.

 

[JosephEK]

I kind of like TFX, though not from experience. In theory it should fill a fantastic niche. What I mean is cases like this:

It's tall enough to justify the case being allowed low profile expansion slots as well as an ample height CPU cooler.
The PSU's fan can pull air from inside the case supplementing airflow by acting as an outtake and its larger size is probably quieter than Flex ATX.

The only thing I'm not sure of is whether adding a low profile GPU in a case like this would choke both the PSU and GPU. Perhaps if that were an issue the PSU should be located on the opposide side of the motherboard.

 

[NateDawg72]

I like 2"x4" industrial power supplies for my own projects ? not something I'd give to someone else though for safety and liability concerns with an enclosure I'd have to make.

HDPlex's internal brick form factors are nice but I'm not a fan of the AC -> 19v DC -> 12v DC thing they have going on. There's an unnecessary set of DC-DC converters and cables that I'd rather not have.

FlexATX is compact but usually the fans kill the deal. SFX is what I use if I have to.

 

[thewizzard1]

DC-DC is the way to go!
Is PicoPSU a form factor, yet?

 

[Edward78]

I kind of like TFX, though not from experience. In theory it should fill a fantastic niche. What I mean is cases like this:

It's tall enough to justify the case being allowed low profile expansion slots as well as an ample height CPU cooler.
The PSU's fan can pull air from inside the case supplementing airflow by acting as an outtake and its larger size is probably quieter than Flex ATX.

The only thing I'm not sure of is whether adding a low profile GPU in a case like this would choke both the PSU and GPU. Perhaps if that were an issue the PSU should be located on the opposide side of the motherboard.

I hate that placement of the PSU, one word why? I mean, the other side guys, before the motherboard. If they had power bricks that would run a high end GPU in a great system that would be nice. None of this BS internal connectors that cut the power by 50w. If I have a 200 Wat brick, I want my sys to get it all. Offtopic, shame BTX/DTX didn't really make it.

 

[Vlad502]

My thoughts:
NanoATX vs FlexATX => Nano wins in silence and modular, but it cost more than Flex (second wins in price/performance)
TFX vs SFX => TFX more silent than FlexATX and good for budget LP system, but SFX wins all other ways
SFX-L vs ATX => ATX more silent (fanless ATX) and cheaper than SFX, but second is more compact

 

[Choidebu]

I love dc-dc (or as hdplex calls it, nanoATX) but I do think it can be improved upon.

For me an ac-dc with built in 5VSB and PS_ON, essentially a pared down server power supply, combined with a dc-atx that understands that would be best.

No more coil whine on no load, no more power cycling when some protection is tripped.

 

[Stevo_]

I like 2"x4" industrial power supplies for my own projects ? not something I'd give to someone else though for safety and liability concerns with an enclosure I'd have to make.

HDPlex's internal brick form factors are nice but I'm not a fan of the AC -> 19v DC -> 12v DC thing they have going on. There's an unnecessary set of DC-DC converters and cables that I'd rather not have.

FlexATX is compact but usually the fans kill the deal. SFX is what I use if I have to.

Not to mention the 19V HDPLex plugins get hot right up against the RAM even when not being pushed hard. I've switched over to all 12V.

 

[NateDawg72]

Not to mention the 19V HDPLex plugins get hot right up against the RAM even when not being pushed hard. I've switched over to all 12V.

Oh yeah, definitely - I forgot about that. I have an early revision hdplex plug in and I wasn't happy with how it pressed against my ram and heated it up. It gets fairly hot.

 

[Windfall]

HDPlex 80w is my favorite internal PSU, hands down.

 

[Marzipan]

what's so good about DC - DC PSU?

 

[Marzipan]

I like 2"x4" industrial power supplies for my own projects ? not something I'd give to someone else though for safety and liability concerns with an enclosure I'd have to make.

HDPlex's internal brick form factors are nice but I'm not a fan of the AC -> 19v DC -> 12v DC thing they have going on. There's an unnecessary set of DC-DC converters and cables that I'd rather not have.

FlexATX is compact but usually the fans kill the deal. SFX is what I use if I have to.

that 250w industrial PSU is quite interesting. I'm guessing you have to solder on your own cables though?

 

[NateDawg72]

that 250w industrial PSU is quite interesting. I'm guessing you have to solder on your own cables though?

No soldering, just crimping your own cables. The datasheet has the information on connector housings and pins for crimping. You could solder to the input pins if you wanted, but it has ring/screw terminals for output and I wouldn't want to solder when I could use that.

I'm hoping to see better ones come out in the next couple years with all that GaN stuff. This power supply is actually a couple years old already, but it is the best I could find in the form factor that meets ATX specs at 12v. (There is a 300w 2x4", but the ripple & noise spec is waaay high so it couldn't be used without something to filter it)

 

[Choidebu]

what's so good about DC - DC PSU?

Mainly size and better cable management (if using a direct plug board), and the fact that you split them off means you get more choices in placement.

And if you go 12V direct, efficiency. Good 12V ac-dc bricks have like 90 to 95% efficiency, that's platinum area in other psus.

A more niche plus - wire a battery directly to dc-atx!

 

[Marzipan]

Mainly size and better cable management (if using a direct plug board), and the fact that you split them off means you get more choices in placement.

And if you go 12V direct, efficiency. Good 12V ac-dc bricks have like 90 to 95% efficiency, that's platinum area in other psus.

A more niche plus - wire a battery directly to dc-atx!

ummm...12v ac-dc bricks have platinum level efficiency...but what does that have to do with dc-cd PSU?

 

[NateDawg72]

what does that have to do with dc-cd PSU?

It is a big factor in entire PSU efficiency, since dc-dc is only half of PSU a PC would need.

If it is 12v dc-dc PSU, it passes the 12v along with minimal losses ?

If it is 19v ac-dc high efficiency, a 19v -> 12v dc-dc is needed and that takes a chunk out of the efficiency.

For example:
19v AC-DC 94% efficiency
19v->12v DC-DC 95% efficiency

Both very efficient, high quality - 94-95% is spectacular.

But combine them together... 94%*95% gives overall efficiency around 89%. Good but no longer impressive. A 91% 12v AC-DC + DC-DC may not look as impressive on paper but would come out a little more efficient since the DC-DC only needs to do conversions for minor rails like 5v, 3.3v, etc

 

[Marzipan]

It is a big factor in entire PSU efficiency, since dc-dc is only half of PSU a PC would need.

If it is 12v dc-dc PSU, it passes the 12v along with minimal losses ?

If it is 19v ac-dc high efficiency, a 19v -> 12v dc-dc is needed and that takes a chunk out of the efficiency.

For example:
19v AC-DC 94% efficiency
19v->12v DC-DC 95% efficiency

Both very efficient, high quality - 94-95% is spectacular.

But combine them together... 94%*95% gives overall efficiency around 89%. Good but no longer impressive. A 91% 12v AC-DC + DC-DC may not look as impressive on paper but would come out a little more efficient since the DC-DC only needs to do conversions for minor rails like 5v, 3.3v, etc

gotcha. what are the options out there for these high efficiency power adapters, both the AC-DC and DC-DC you mentioned.