Power Supply Convince me that Flex ATX PSUs can be quiet

confusis

John Morrison. Founder and Team Leader of SFF.N
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Jun 19, 2015
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That is the reason I've been staying with SFX PSUs so far.

Personally, I have question marks on Noctua (or any other quiet fans) conversion on Flex ATX PSU:
- Is it done by a qualified person?
- Will it push enough airflow?
- Is there any warranty if something goes wrong?

I do wish that TFX PSU with its 80mm fan gets more popular.
TFX is such a sadly forgotten PSU form factor :(
 

Kaji

Doesn't own a caliper
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Jun 1, 2020
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+1 for the Silverstone FX600. I have owned two and both have been exceptionally quiet at a max draw of approximately 350W.

Used on a Densium build (OC 5600X/3060ti) with NF-A12x25s and never noticed PSU noise.
 
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Kaji

Doesn't own a caliper
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REVOCCASES

Shrink Ray Wielder
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I got a second hand STREACOM ZF240 for my next build and I thought this might also be interesting for some of you...

the unit is similar in size like a normal FLEX but adds a little bit flex(ibility) for mounting in custom cases due to the separate IEC connector (similar to HDPlex).

I've stress tested it with pulling about 160W off the 12V rail (A2000 & i5 11400) for one hour and it barely got warm. Also: no any noise, even no coil whine.

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the ZF240 was released back in 2014 but already had a pretty good efficiency with up to 93% -- what it does not offer unfortunately is a PCIe power connector and it only comes with a 4PIN CPU power connector

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quite thick insulation cover on the IEC connector - safety first...

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however, the AC connector could be easily replaced by a smaller IEC C6

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the bracket is meant for additional cooling and mounting but I found it is not really necessary for lower wattage builds...

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build quality is good, the OEM for STREACOM is IOASPOW - they also make a couple of 12V DC-ATX PlugIn PSUs

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high quality caps from NIPPON Chemi-Con

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overall a nice PSU, except for the mustard cables and (for me) unnecessary MOLEX connectors... but that can be fixed...

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I certainly wouldn't get the ZF240 brand-new for EUR 165,- but if you can find a second hand unit for a fair price, I think it's worth a look
 

Overtek

Airflow Optimizer
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May 22, 2017
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TFX is such a sadly forgotten PSU form factor :(
TFX was once popular, but mainly for the OEMs HP, Dell etc for slim desktops, e.g. HP s5000 series. I've sold thousands over the years as replacements as the 'design life of them was made to deliberately short.

Toyed with a 500W years ago, a transplant from FSP flex atx into a Seasonic housing.

If there is real demand, like 50-60pcs. I will happily get a batch of 600W platinums produced based on enp-7660b. same sort of price point.

This would be able to run near silent most of the range and still be quiet at max load. If I canI, would get a slight tweak to the fan map so it could run semi passive. Passive to say 150-200W then an fdb fan startup voltage above this, (6V)
Have some related work going that involves a new fdb fan that would fit, will know how that performs next month as that's awaiting a pcb tweak and engineering sample before test.
 

Gilles3000

Airflow Optimizer
Oct 6, 2018
240
243
TFX is such a sadly forgotten PSU form factor :(
I toyed around a bit with creating a custom case around the TFX Silverstone TX-700 a few years ago, didn't really find a formfactor that had any real advantage over existing ones with an SFX PSU.

That and the fact that it doesn't really outperform any comparably priced SFX PSU's nor allows for slimmer formfactors unlike Flex-ATX, I'm not really surprised that its a forgotten form factor. 🤷‍♂️
 

Overtek

Airflow Optimizer
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May 22, 2017
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I toyed around a bit with creating a custom case around the TFX Silverstone TX-700 a few years ago, didn't really find a formfactor that had any real advantage over existing ones with an SFX PSU.

That and the fact that it doesn't really outperform any comparably priced SFX PSU's nor allows for slimmer formfactors unlike Flex-ATX, I'm not really surprised that its a forgotten form factor. 🤷‍♂️
Yep it doesn't offer really any more pcb real estate, Just extra height for big fan. Where as sfx gives more pcb area as well as same sort of size fan as tfx
 
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k0n

Cable-Tie Ninja
Jul 3, 2019
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didn't really find a formfactor that had any real advantage over existing ones with an SFX PSU

Unsurprising... with TFX you just trade in 40mm less width for 75mm extra length.

Flex-ATX is great... I haven't tried any unit yet because I couldn't imagine it being silent., but the dimensions... I like how on the FlexGURU the fan is hidden and how even the 'modular' connectors are within it's dimensions. Fan aside this formfactor has advantages over even the much smaller 250W GaN from HDPLEX. A solid fanless 350-400W unit would be worth 200$ at least to me.
 
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Overtek

Airflow Optimizer
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May 22, 2017
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Unsurprising... with TFX you just trade in 40mm less width for 75mm extra length.

Flex-ATX is great... I haven't tried any unit yet because I couldn't imagine it being silent., but the dimensions... I like how on the FlexGURU the fan is hidden and how even the 'modular' connectors are within it's dimensions. Fan aside this formfactor has advantages over even the much smaller 250W GaN from HDPLEX. A solid fanless 350-400W unit would be worth 200$ at least to me.
Work out the dBA of a 40mm noctua running at 60% duty cycle, that's your noise level of enp7660b with noctua delivering power up to 450W loads