AC/DC Adapter for thin mITX system with 1050Ti

McSpain

Trash Compacter
Original poster
Jun 8, 2018
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Hi guys,
I'm pretty new to the scene here, so excuse me, if it's a dumb question.
I plan on doing a thin mITX system for my younger brother for maximum compactness, but still use a discrete GPU. Since Inno3D has this lovely single slot 1050Ti, I got the idea of incorporating it alongside a i5-7600. The combined TDP of both is 140W, with 75W going to the GPU. I don't know about any internal AC/DC adapter apart from the HDPLEX 160 or 400, but 160W seems too little, and 400W too overkill for this system. Are there any alternatives?

Also I'm a bit worried about the powering of the GPU. The 1050Ti draws up to 75W, but only 25W could be drawn through the x4 PCIe from the board. I'd use a powered riser from ADT-Link, but the additional 12V rail would draw up to 4A from the SATA-Power adapter on the mainboard. Could this cause damaed to the onboard DC/DC components of the mainboard, that converts 19V to 12V?
Or should I solder a 19V to 12V adapter in parallel to the board?
 

kotproger

SFF Lingo Aficionado
Jul 9, 2016
135
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vk.com
Hi guys,
I'm pretty new to the scene here, so excuse me, if it's a dumb question.
I plan on doing a thin mITX system for my younger brother for maximum compactness, but still use a discrete GPU. Since Inno3D has this lovely single slot 1050Ti, I got the idea of incorporating it alongside a i5-7600. The combined TDP of both is 140W, with 75W going to the GPU. I don't know about any internal AC/DC adapter apart from the HDPLEX 160 or 400, but 160W seems too little, and 400W too overkill for this system. Are there any alternatives?

Also I'm a bit worried about the powering of the GPU. The 1050Ti draws up to 75W, but only 25W could be drawn through the x4 PCIe from the board. I'd use a powered riser from ADT-Link, but the additional 12V rail would draw up to 4A from the SATA-Power adapter on the mainboard. Could this cause damaed to the onboard DC/DC components of the mainboard, that converts 19V to 12V?
Or should I solder a 19V to 12V adapter in parallel to the board?
The best option would be to use a separate power source for 12v (do not take them from the motherboard itself). All the same, there is a calculation for connecting several hard drives, not more powerful graphics accelerators.
By the way, I also use a thin ITX card - Asus Q87T. To power the graphics adapter so far, the power supply from XBOX will be used.


But in the future I hope to use the solution from KMPKT:
https://www.sfflab.com/collections/kmpkt/products/kmpkt_dynamo_psu?variant=1352978726921
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
Hi McSpain,

What is your motherboard ?

If it' supports 19V input only, Asrock H110TM-ITX for example, I suggest you use @Kmpkt Dynamo solution with a single 19V AC adapter to power both your system and your 1050 Ti.
Cleanest and safest way IMHO : onboard SATA power are not designed to withstand such loads.

I used to did this with a jumpered Hdplex, but the Dynamo is a much better option, as it has been designed for thin ITX boards.


If your motherbaord supports 12V input, Gigabyte GA-H110TN for example, you can use a single 12V AC Adapter to power both your system and GPU (provided you have a 35W CPU).
This is what I'm currently doing. Only two wires !


I also have developed a custom powered riser to add discrete GPU to you thin ITX system.

Let me know if you have any questions.
 
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McSpain

Trash Compacter
Original poster
Jun 8, 2018
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I plan on using the GA-MDQ17AI with 19V.
The KMPKT Dynamo seems a bit overkill, since most of its outputs would stay unused.

Would something like the Pololu D24V150F12 work? I'm just not sure what connect the EN (enable) pin to, to sync the motherboard and the step-down regulator. The manual says, it's pulled high to 5V.

For the PCIe riser I plan to use a R23SL riser from ADT-Link with soldered-on 4pin connector.
 
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aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
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Nice board !

The Pololu D24V150F12 should work, nice find. You can connect the EN pin to any 5V source of your motherboard (fan header, Sata Power...).

I have the riser you mention. +12V tracks are not cut.
I did experience some weird issues with my Gigabyte GAH110-TN due to the 12V current being fed back to the PCIe slot.
 

McSpain

Trash Compacter
Original poster
Jun 8, 2018
46
54
I did experience some weird issues with my Gigabyte GAH110-TN due to the 12V current being fed back to the PCIe slot.
The weird thing is, that pin1 of that floppy connector is configured to 3.3V, but severed from the rest of the board by this TP2 solder pad. Maybe that's the root of your issues.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
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Did you already test this riser ?

I solved the issue by developping the custom riser I already mentionned :D
With an integrated load switch (triggered by the PCIe slot) and +12V tracks already cut.

What kind of case do you plan to use ?
 

McSpain

Trash Compacter
Original poster
Jun 8, 2018
46
54
I'm currently developing my own scratch build. I'll post pictures in the project thread soon.
 

McSpain

Trash Compacter
Original poster
Jun 8, 2018
46
54
In that case, you need a riser with completely independent power. As for example mine in the photo above) I originally designed it under my thin Q87t board.
But in the end the project became more universal)
https://smallformfactor.net/forum/threads/project-cpr-customizable-pci-e-riser-up-to-x16.6120/

Well, in the worst case scenario, I'll tape over the 5 12V pins, so all the 12V power is drawn from the DC/DC converter. As far as I can see, this should come close to your solutions.
I originally thought about using the 1070 Katana, which would have made the KMPKT Dynamo 360 mandatory, but it was beyond budget and is no longer available anyways.
 

kotproger

SFF Lingo Aficionado
Jul 9, 2016
135
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vk.com
Well, in the worst case scenario, I'll tape over the 5 12V pins, so all the 12V power is drawn from the DC/DC converter. As far as I can see, this should come close to your solutions.
I originally thought about using the 1070 Katana, which would have made the KMPKT Dynamo 360 mandatory, but it was beyond budget and is no longer available anyways.
If you compare your version of DCDC and dynamo, then the difference in price is not great, but we get a more substantial margin for power.
I personally would prefer the 360 dynamo, but for this new converter there are no reviews, no testing with technical analysis.
 

McSpain

Trash Compacter
Original poster
Jun 8, 2018
46
54
Just discovered this open frame PSU with 19VDC output. Looks quite promising to me, though I'm still trying to figure out, how the "inhibit" function works. Seems like the opposite of the "enable" function of that DC-DC converter.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
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Nice find !

However, you cannot disable the output for the GPU and leave it open for the system. The PSU is either ON or OFF.

However, why don't you simply use a 19V AC Adapter and use the onboard two-pin connector to output 19V to your Pololu D24V150F12 ?
This connector is acting as a passthrough output when the DC jack is populated.
You end up with two input wires, your little board and 6 output wires to your GPU.

This is what I did (credit to @QinX) with a HDPLEX 250W and it works great.


A slim 240W AC Adapter doesn't take lots of estate and offers plenty of power for your intended configuration.
 

McSpain

Trash Compacter
Original poster
Jun 8, 2018
46
54
Mhmm, I thought the disable function would leave the 5V standby unaffected, so that the motherboard could route back the 5V for toggling the PSU somehow...
 
Last edited:

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
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Yes, you may be right.
Seems you're looking for trouble though !!

You board also accepts 12V input.
You'd just need a 12V PSU, a load switch for the GPU and that's it.

With a 12V brick and my powered riser (which includes a load switch), my HTPC has only two wires : the way I like it !

The onboard 2-pin connector is only labeled as 19V though ; to be confirmed by Gigabyte.
 

CC Ricers

Shrink Ray Wielder
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Nov 1, 2015
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@aquelito, out of curiosity, have you ever tried to use a GTX 1050 Ti or other 75W card with a non-powered riser on your thin ITX board? As you may know I have used this kind of setup, and didn't know how well it will take it but I had used a ASL GTX 1050 (75W) and WX 5100 (50W) and to my surprise both worked fine with a non-powered riser. That might actually work in some circumstances. I had used the same board you have, Gigabyte GA-H110TN (GSM version). And use this rather fancy looking riser.

It never hiccuped on my setup with a G4400 CPU. No power shutdown not even with the GTX 1050. Maybe it's either due to the robustness of the power delivery system of the motherboard or the particular riser cable that I use. I was running that straight from a 150W power brick to the 19V DC jack.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
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I never tried that ! Maybe the PCIe 4X is more capable than theory says.
But the VRMs on thin ITX boards do not seem to be fit for high-powered GPUs anyway.

Did you notice any throttle of the 1050 ?

I have the ASL 1050 Ti. Since the 12V tracks of my riser are cut, I can measure the exact power consumption under load.
 

McSpain

Trash Compacter
Original poster
Jun 8, 2018
46
54
You board also accepts 12V input.
You'd just need a 12V PSU, a load switch for the GPU and that's it.

With a 12V brick and my powered riser (which includes a load switch), my HTPC has only two wires : the way I like it !

I think, your riser is a bit to wide for my plans (single slot GPU).
But in case the board actually accepts 12V (similar to the ASRock IMB-1213) and given the 5VSB is always on, it should be possible to make a load switch for the entire setup by coupling PS_ON to 5VSB, and shorting it througha 5VDC-controlled npn and a PWRBTN-controlled pnp.
 

CC Ricers

Shrink Ray Wielder
Bronze Supporter
Nov 1, 2015
2,200
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I never tried that ! Maybe the PCIe 4X is more capable than theory says.
But the VRMs on thin ITX boards do not seem to be fit for high-powered GPUs anyway.

Did you notice any throttle of the 1050 ?

I have the ASL 1050 Ti. Since the 12V tracks of my riser are cut, I can measure the exact power consumption under load.

I don't think I've noticed any. The card seemed to perform as well as any stock 1050. But also the fan is always pretty loud and it was usually in the 80s in temperature.