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Someone Explain HDPLEX or PICOPSUs please


Alright, I think I’ve settled on the Streacom F7C Alpha case for my HTPC 2400G build, but that’s going to require something like a PicoPSU or HDPLEX.

Right now I’m thinking of the HDPLEX 160W DC-ATX converter, but I’m a little confused on the power brick concept. Presumably I would want a brick that does 150w or so to deal with any lack of efficiency, as right now it seems max system draw sits around 120w with an overclocked APU. I’ll be using an NVMe drive, one 2.5" mechanical drive, and an optical of some sort that will probably get used rarely, but I want the option.

However the brick is confusing to me, in that there seem to be a ton of wattage options, and I am unfamiliar with brands, IE which to avoid or look for (outside of HP/Dell OEMs that are frankly very expensive).

I am open to suggestions, also if anyone has used these ultra-small power supplies/converters I’d be interested in your experiences.

Here’s the HDPLEX in question:


Some notebook powerbricks have awful ripple under load conditions, so sticking to higher quality brands is recommended.

The specs for the HDPlex supply are curious. 16V is barely out of “standard voltage”. Finding a good supply in the 16 to 24V range will be limited by 15V and 24V beeing more standard than 16V (allthough some better 15V PSUs may be adjustable up to 16V).

That said, either get a powerbrick and cut the plug of it or get a PSU like this.
In case of the second unit, you need to buy your own power lead and screw it in place. The voltage can be adjusted down to 20V putting it right in the centre of input voltages for the HDPlex supply.


I don’t mind having the power brick, I was mostly trying to understand the issue of having one and how they work, as the only time I’ve ever used one is with the product it came with, and as such I am unfamiliar with the workings of a variable voltage input like the HDPLEX since it will take 16-24v. It seems like a 19v with appropriate wattage would be ideal as that is what they supply in a kit (expensive and non-external though, and the F7C Alpha is pretty darn small). Over 150 watts they seem to get rather expensive as well.



Have you ever looked into other PSU for factors other than ATX?

Nowadays it’s possible to get relatively powerful and efficient SFX, TFX, and Flex power supplies without having to sell your kidneys. You wouldn’t have to deal with janky power bricks and/or poor efficiency with what would essentially be an AC/DC/DC converter.


Notebook power bricks are bad in the efficency department.

However there are a lot of switchmode PSUs that have 85 to 90% efficency. That combined with the DC-DC converter from HDPlex would lead to 70 to 87ish % overall efficency.

I really need to take a part a modern ATX psu… no idea how they do their voltages right now.


There are a number of things to consider. For starters, is your ~120W power consumption measured at the wall (Kill-A-Watt or similar) using an ATX power supply? My experience with PicoPSU’s from mini-box + power brick draws around 10 watts less than typical ATX PSU’s running the same computer. In my case I use a power brick from mini-box that is 12V and generally runs at 50% load max. Everyone I talked to about it before doing it myself said that it had to draw more power, but my limited experience has been lower power consumption.

Your system speed and voltage will drastically change power consumption. If it takes a 10% increase in voltage to get another 100 MHZ then that small performance bump may not be worth it. Dialing the system in to a good performance vs power use ratio could potentially save a bit of money by being able to use lower power (and less costly) components. If it functions acceptably at stock clocks then you can drop the volts and lower both power consumption and heat.

I don’t know how things are on the AMD side of things, but I have been able to bury my CPU voltage at stock clocks and significantly drop my power use. Going in to BIOS and disabling COM ports and other stuff you aren’t using can reduce power a tiny bit as well as possibly speed up boot times.

Some of the larger power bricks have fans, and running it a fair bit below maximum will extend life and reduce or eliminate fan usage. If you look at the pic at the bottom of your hdplex link it shows a 300W 19V brick powering the PSU. Running it at half capacity or less means it will stay cool and last a long time.

Some people buy those laptop bricks and put them in parallel. This divides the load across them, but quality can be variable with too many knock-offs around. I haven’t seen anything pro or con from people doing that long term.

For optical I have just been using a USB DVD drive. I break it out once a year maybe and it otherwise sits with my random computer crap. It doesn’t make much of a difference either way, but I can’t be bothered putting them in every machine I build just to never use it.

I’ve looked at the hdplex PSU’s before, but their narrow (16V-24V) range isn’t compatible with either 12V or 24V solar, so I really have no opinion on their product beyond them being pigeon-holed between two very popular voltages which could greatly extend their use to solar, automotive/RV and more. It’s a shame their 400W PSU can’t take 24V nominal input. It would be great for the L1-UPS.

My M4-ATX PicoPSU was bought so long ago I barely remember, about 9 years ago or more. I’ve used it in a car briefly, on grid for a while, and now on solar 24/7. It was a bit pricey but I have gotten my money’s worth out of it. I’ve been using Their Cheapest Kit on some low end machines for a couple of years, again without issue.

If you go for the hdplex you may need to get a PSU similar to the one linked above to supply it with a sufficient amount of clean power at the proper voltage. Or buy the one hdplex sells and put it in its own box. They aren’t cheap, but it should last a really long time.


Yes, but I don’t want a larger case. This will sit under my TV on the entertainment center and I want it small and unobtrusive. Hiding a power brick is easy though, so that’s the route I’d like to take although it will probably cost a bit more.

Right now I’m basing it off of other 2400G reviews, which presumably have no peripheral power draw such as spinning drives, where I intend to use an M.2, HDD, and disc drive, so even overclocked they seem to draw about a maximum of ~120w under stress tests and I want a little more leeway than that considering the hardware. I am pretty sure they are using ATX supplies and this is at the wall draw.

I agree wholeheartedly.

Well right now I don’t even have one of those, and considering this will be an HTPC I would like to at least have an always-available DVD drive on it, but honestly I’m still only 70% on that. I rarely miss a disc drive on my main PC, and most of the time simply never think about it.

The main reason I like the HDPLEX is that it comes with an 8-pin CPU cable where the PicoPSU doesn’t seem to, but I don’t know if that matters for RR or not.


NEVER put PSUs in parallel or series!

The weakest link will give, and it will end in a bang and probably some smoke and smell.

Then the PSUs you are looking at are bad.
I marked the unit that fits the best for the given range. The yellow marking indicates the range in wich the voltage is adjustable.


I was referring to the hdplex PSU’s linked in the OP. The input voltage range is 16V - 24V. I get it that they are only concerned with 19V input and maybe there were cost reasons for excluding both 12V and 24V nominal battery setups, but higher output DC-DC PSU’s seems to be an unfulfilled market and they are so close with their current offerings.


Well I’m pretty sure I’m going a slightly different direction:

This thing is tiny and comes with a fully fledged (if proprietary) 150w PSU.