Power Supply Convince me that Flex ATX PSUs can be quiet

[Arboreal]

I bought the prototype 4.5L MT4-S case from @CC Ricers in 2020 and am considering using it with a higher power setup again.

It's currently nice and quiet as I've been using a Q87T thin ITX board that is brick powered with a couple of 3.5" drives for external offline storage.

I went that way as I was put off by the noise from the (admittedly cheap) FSP270-60LE Flex ATX PSU I had in it initially. It was perfectly quiet on IGP, but the relatively undemanding H81N / i5 4570 / GTX 1050Ti combo made it wail like the proverbial banshee.

I briefly considered a Noctua conversion, but I wasn't sure a 10mm deep Noctua would have anough quiet airflow to safely replace the existing 2 pin 15mm deep 40mm fan.

This has obviously coloured my view of Flex ATX PSUs, and I'm reluctant to throw more money at one if it's going to scream under load. I think the X470i / R5 2600X / GTX 1650 will need around 200W, so a 250 or 300W model would be fine.

I see that @Otamot has some good looking Seasonic models in that range from 50 GBP or so upwards.

I'm all ears!

 

[ignsvn]

I briefly considered a Noctua conversion, but I wasn't sure a 10mm deep Noctua would have anough quiet airflow to safely replace the existing 2 pin 15mm deep 40mm fan.

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.

 

[Arboreal]

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.

Thanks @ignsvn, I have a number of SFX powered ITX rigs at home and have no worries about any of them noise wise.

Even the older ones with 80mm fans aren't bad; the Corsair SF with 92mm are better, and my solitary SFX-L is great for its size.

Your questions about fan conversions are spot on, IThe ones from Overtek will be bulletproof as they're done by an experienced engineer in a company,
otherwise not so much...

Interestingly, I have a couple of TFX PSUs out of prebuilts in the drawer as they are intriguing and would work well in the right shape of case, which theer aren't enough of.

 

[ignsvn]

Interestingly, I have a couple of TFX PSUs out of prebuilts in the drawer as they are intriguing and would work well in the right shape of case, which theer aren't enough of.

Out of the FlexATX topic, but FYI

Production - Lazer3D CG7 Cravo - Low profile silent case (slim mATX | mini itx) | SFF.Network (smallformfactor.net)

IIRC the latest revision supports both TFX & Flex ATX PSU.

 

[REVOCCASES]

This has obviously coloured my view of Flex ATX PSUs, and I'm reluctant to throw more money at one if it's going to scream under load. I think the X470i / R5 2600X / GTX 1650 will need around 200W, so a 250 or 300W model would be fine.

quiet FLEX is possible but you'll need to get a good (platinum rated) unit and run it below ~2/3 of the rated load

I heard, the SILVERSTONE 600W FLEX is relatively quiet without a fan mod... and of course OVERTEK sells the ENHANCE with Noctua Fan mod and custom length cables

other, really silent options for 200~250 W could be the HDPlex or STREACOM PSUs but at that price point I'd personally rather invest in a 600W FLEX which still could be used for future, higher wattage builds...

 

[KepKe]

This lad moded a Flex in such a way that he could make it a tophat with a 80mm fan. It's a bit thicker, but probably quieter than any other flex.

 

[Arboreal]

quiet FLEX is possible but you'll need to get a good (platinum rated) unit and run it below ~2/3 of the rated load

I heard, the SILVERSTONE 600W FLEX is relatively quiet without a fan mod... and of course OVERTEK sells the ENHANCE with Noctua Fan mod and custom length cables

other, really silent options for 200~250 W could be the HDPlex or STREACOM PSUs but at that price point I'd personally rather invest in a 600W FLEX which still could be used for future, higher wattage builds...

That is sound advice, running under 2/3 the rating and choosing an efficient design. The 250W HDPlex GaN unit is interesting but out of budget.
I can't even use a Mean Well RPS/EPP unit with Pico PSU as the largest Pico won't have enough power to safely run a system with just a 75W bus powered card IMHO. I think the RPS/EPP wouldn't even fit in the tightly proportioned case.

This lad moded a Flex in such a way that he could make it a tophat with a 80mm fan. It's a bit thicker, but probably quieter than any other flex.

Thanks for the video, I'd seen the finished PSU mod somewhere, but hadn't seen how it had been achieved. If a slim 80mm fan is enough to cool a Flex ATC PSU, there is lots of potential if you have the space.

The case I have is really tight for space and there would be no room to do that mod. A possible alternative would to put taller feet on it and have the 80mm fan on the bottom of the base panel having (carefully) made a hole in the PSU enclosur.e

 

[smitty2k1]

That is sound advice, running under 2/3 the rating and choosing an efficient design. The 250W HDPlex GaN unit is interesting but out of budget.
I can't even use a Mean Well RPS/EPP unit with Pico PSU as the largest Pico won't have enough power to safely run a system with just a 75W bus powered card IMHO. I think the RPS/EPP wouldn't even fit in the tightly proportioned case.



Thanks for the video, I'd seen the finished PSU mod somewhere, but hadn't seen how it had been achieved. If a slim 80mm fan is enough to cool a Flex ATC PSU, there is lots of potential if you have the space.

The case I have is really tight for space and there would be no room to do that mod. A possible alternative would to put taller feet on it and have the 80mm fan on the bottom of the base panel having (carefully) made a hole in the PSU enclosur.e

FWIW I've been running an AM4 Ryzen + GRX 1650 for years on a 200w Meanwell + 160w picopsu on 1080p monitors and TVs. Lots of lan parties and stress tests without issue.

That said, I just got a 4k TV and every time I try to change the resolution to 4k it instant crashes. I'm blaming the PSU and looking to upgrade now.

 

[Arboreal]

FWIW I've been running an AM4 Ryzen + GRX 1650 for years on a 200w Meanwell + 160w picopsu on 1080p monitors and TVs. Lots of lan parties and stress tests without issue.

That said, I just got a 4k TV and every time I try to change the resolution to 4k it instant crashes. I'm blaming the PSU and looking to upgrade now.

That is really good to hear thanks @smitty2k1, I'll only be on 1080. Which Meanwell BTW? I looked quickly and the difference between the EPP and RPS versions wasn't immediately apparent

 

[Analogue Blacksheep]

Would a hypothetical GAN based Flex ATX unit help with the noise issue?

 

[Arboreal]

Would a hypothetical GAN based Flex ATX unit help with the noise issue?

It possibly could.
The way I see it is that the whole thing hinges on how much cooling is required.
With room for only a 40mm fan, the PSU has to be cool enough running to not require a fan running at ear splitting speeds.

 

[REVOCCASES]

It finally all comes down to efficiency when you are looking for a cool&quiet PSU... HDPlex states up to 94% for their GaN unit but this can also be achieved with a good common PSU design w/o GaN...

The only problem is: efficient PSU designs are very expensive and the average user prefers cheap products

 

[Arboreal]

@REVOCCASES that is one heck of a SFF power supply and might be out of budget!
That said, I could probably pull 1kW of power quietly...

At the moment, I'm considering a case redesign to add height and width to accommodate an SFX power supply. This could take it up to 6 or 7L though

 

[smitty2k1]

That is really good to hear thanks @smitty2k1, I'll only be on 1080. Which Meanwell BTW? I looked quickly and the difference between the EPP and RPS versions wasn't immediately apparent

RPS-200-12-C:

Please ignore the non PicoPSU plugin unit, I was just testing some things out. More pics in my signature.

 

[robbee]

@smitty2k1 Have you attempted that setup with the MW outside of the case or with some airflow? Running it passive diminishes its output rating so perhaps it's triggering overload or overheat protection?

I'm a bit confused as I've ran a similar setup with RTX A2000 and i3 10100 with a 160W Meanwell + 160XT on my 4k television without issue for almost 2 years now...

 

[REVOCCASES]

I think it might be more related to the PicoPSU. I've stress tested the RPS200 a while back with 200W load and no additional cooling. It got toasty after a while but didn't shut down.

 

[Analogue Blacksheep]

@REVOCCASES that is one heck of a SFF power supply and might be out of budget!
That said, I could probably pull 1kW of power quietly...

At the moment, I'm considering a case redesign to add height and width to accommodate an SFX power supply. This could take it up to 6 or 7L though

Prices for it seem to be all over the place, but I did find this: https://www.itcreations.com/product/73588

Although it's a hot plug server PSU.

 

[REVOCCASES]

Although it's a hot plug server PSU.

and it comes with a 25K RPM jet engine fan...

just wanted to give an example that it is already possible to achieve >=94% efficiency without GaN - unfortunately not for consumer FLEX PSUs so far but one day maybe

 

[smitty2k1]

@smitty2k1 Have you attempted that setup with the MW outside of the case or with some airflow? Running it passive diminishes its output rating so perhaps it's triggering overload or overheat protection?

I'm a bit confused as I've ran a similar setup with RTX A2000 and i3 10100 with a 160W Meanwell + 160XT on my 4k television without issue for almost 2 years now...

I haven't - I need to do some testing with other cables and my other 4k TV and my other mini-PC that has HDMI 2.1 that I know works on a 4k TV. Running it out of the box with airflow is a good idea too, though this is an instant crash the second I change the resolution. Keeps crashing every time it boots back up and switches from BIOS to Windows (resolution change). Tried reformatting and reinstalling Windows too. It's just super weird because I used it for YEARS on 1080p with no crash, including gaming, stress testing, and portable at LAN parties with a little 1080p HDMI monitor.

I also ordered a $12 "300w" plugin unit that @REVOCCASES recommended in another thread. HDPlex says their 200w 12v plugin units won't be arriving till this summer.

 

[HWI]

I have an ENP 7660B 600W Flex ATX PSU I purchased with my Velka 5 from Velkase, no issues with noise. Though I will say that I am not stressing it at all with a 12400 and RX 6650 XT. I can't say what the sound profile is like if it was loaded up closer to capacity.