GPU Thin Mini-ITX with discrete graphics card

iFreilicht

FlexATX Authority
Feb 28, 2015
3,243
2,357
freilite.com
Not on the outside, unfortunately. The Gigabyte boards do have a 4-pin internal 12V connector, which is awesome, but I've yet to see an externally powered board with a strong DC-in connector in the wild let alone in retail.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
Cheapest and "dirtiest" option for the Gigabyte board would be to use a Dell DA-2 brick with that kind of eGPU adapter from @KareonKables.
You'll have to jumper the Dell DA-2 manually or with a switch though.

 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
Finally found the time to complete the first phase of my build, based on mCubed HFX Micro case I purchased brand new for 14€ !!
This is an old case model, launched in 2006 by the Austrian company HFX.

Dimensions are 223 x 240 x 80 mm, which makes a nice 4.3L build.

My inital plan was to use an Antec ISK-110 but this case is more adapted to my use case scenario (home freelacing computer, which has to be easily maintained).




Bad pictures as I forgot my camera at work...

For now, I only modified the rear panel to support and secure a dual slot GPU.

This is a semi-passive build : the i5 6400T CPU is cooled by one of the side heatsink thanks to a flat cool pipe I already mentioned, while the Inno3D GTX 1060 enjoys a slim 140mm Prolimatech fan.
I could have left the original 92mm fan that only starts above 50° but I wanted to help cool down the mSata drive, HDPLEX, SO-DIMM...

Even with the 140mm fan always on, the computer works in complete silence.
I only hear the fan above 800RPM (max 1000).

I am really happy with the temps too. CPU is stable at 65° after 30 min of Prime95 and Engine Valley running simultaneously.

Best build I had so far, thanks to thin Mini-ITX !
I'll do a build log in a few days.
 
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aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
I purchased and tested a Gigabyte GA-H110TN motherboard, which conveniently accepts 12V input.

Enclosed a picture of the tested layout :



I am using a Dell DA-2 12V 18A AC adapter to power my system (Intel Pentium G4600T + 8 Gb CMSX8GX4M2A2400C16).

Current wiring is the following :

The Dell DA-2 adapter is plugged into the DC-IN 5.5 barrel connector.
I am using the internal 4-Pin Mini Fit Jr to output 12V current from the Dell DA-2 to the powered riser.
A MSI GTX 750 Ti Low Profile is connected to the riser.

As I am using a powered riser, the PCIe x4 slot stays within the 25W limit.
The other 40W the GTX 750 Ti needs under load are provided by the 12V AC adapter.

It works fine, except for two issues I would like to submit to you.

Issue #1

Whenever I am using the 4-Pin ATX_12V internal connector, as 12V output or 12V input, the CPU fan is spinning even if the motherboard is powered OFF.
I am pretty sure a hard drive would be spinning too.

I did two tests to try to narrow down the possible reasons for this strange behaviour.

1.a. 4-Pin ATX_12V internal connector left unused :
I removed the 4-Pin to Molex cable and the riser. Nothing is connected to the 4-Pin internal connector.
The DC power jack is connected.
Result : the motherboard acts "normally" : the CPU fan does not spin until the motherboard is powered on.

1.b. 4-Pin ATX_12V internal connector used as 12V input :
I used the 4-Pin as 12V input, using a DC-DC board (Picobox X7-ATX-500) providing 12V current to the motherboard.
The DC power jack is not connected.
Result : the CPU fan is spinning even if the motherboard is powered OFF.

CONCLUSION : whether the 4-Pin ATX_12V internal connector is used as output or input, the motherboard seems to be continually fed with 12V current even if it is not powered ON.

What do you think could cause this strange behaviour ?
Do you think it could be dangerous for the motherboard ?

Issue #2

After several reboots, the system won't POST.
Both CPU and GPU fans keep on spinning at full speed but no display.
I have to wait few minutes or remove the GPU to be able to start the system.

Could it be VRM related ?

Here is the background story, as updating to the latest BIOS also caused some issues.
 

Aibohphobia

aka James
Gold Supporter
Feb 22, 2015
4,956
4,727
As I am using a powered riser, the PCIe x4 slot stays within the 25W limit.
The other 40W the GTX 750 Ti needs under load are provided by the 12V AC adapter.

Usually powered risers are all or nothing, so the 12V AC should be providing all of the video card's power.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
@Aibohphobia

When I asked Vary about the riser pinout, they answered that the 12V is "enhanced", which lead me to suppose that 25W were provided by the slot, and the remaining 40W by the riser (enhance vs. provide).
However, it is written in an approximate english ; there is room for interpretation.

Regarding the board, I submitted the issue to Gigabyte ; here again, I am not sure to understand their answer :

The fans remain on because of the 12V power supply can not be shutdown by the motherboard.

That´s normal. You must switch off the mains power.

On #2:

We don´t know, if the 12V In of the VGA card does apply 12V DC to the PCIe bus after the motherboard id shutdown.

If it does apply the 12 V to the PCIe bus this might cause such abnormal behavior.

Finally we must say, your DC power connection is not supported.

Each ATX PC standard powersupply does cut all 12V powerlines if the system is shutdown.

The comment regarding the GPU is interesting but I'm not sure to understand their point.
On the riser, the 12V current is applied to the on-board 16x slot only, not to the motherboard PCIe 4x slot, right ?

Also, what do they mean by DC power connection not being supported.

They still do not answer the main issue though : why is 12V is still applied to the motherboard after shutdown, ONLY when the 4-Pin internal connector is used (either as input, or output ; doesn't matter).

This connector can be used either as ouput or input :

- if used as output, it will ouptut the AC adapter voltage (either 19V or 12V ; I chose 12V as I need to power a GPU).
- if used as input, you must provide 12V. Same as a standard 4-Pin CPU connector.

Any idea ?

I will try again with a jumped ATX PSU but I'm pretty sure it will lead to the the same result.

I'll also try powering a simple fan instead of the GPU, just to see if the riser may be the issue.
 
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fredmanders

Case Bender
May 11, 2017
2
0
Hi all!

I've been roaming the Internet to see if somebody successfully got a GPU working on a thin mini itx, like mine (GA-H87TN).

I've read all your posts on modding your case/motherboard/power supply to get it to work. But what happens if you just plug in a video card that is designed for x16, into the x4 slot of the PCI-e slot like on my Thin mini ITX? It wouldn't get enough power. Would it try to get it anyway and overheating the system?

What if I buy a GPU that only needs 25W max? Like the Nvidia GT 720? Claims to only need 19W. Could I just plug it in without any mods? Or with maybe an unpowered riser?

Curious to know what you think!

Great topic!
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
What is the point of using a thin mini-itx board if you simply plug your GPU vertically ?

There is also a risk for your board VRM, which are not designed to power a GPU.
 

fredmanders

Case Bender
May 11, 2017
2
0
I started a build in my old NES case, for that I needed it to be thin mini-itx. Now I'm trying to see if I could buy a dedicated graphics card to be able to play some games on it as well. But it's unclear from benchmarks I've found if the GT 720 or the GT 1030 at 80% will give a significant performance boost to the system. I would install it with a flexible riser, so it can still fix in my case:

https://drive.google.com/open?id=0BzduOiBUFcNecEFwekxmOWZhREU
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
Do you have the same fan issue without the video card/extender installed?

Solved the issue by removing the fans ahah ! :D
I used a good ol' Accelero S1 to cool a GTX 1050 Ti.

Also took the opportunity to get a Gigabyte H110TN motherboard and a G4600T. The Gigabyte board accepting 12V input, I could also remove the HDPLEX unit.
I'm now using a single 12V brick to power the whole system, using the internal 4-Pin Mini Fit JR connector, which is acting as a splitter, to output power from the brick to the riser.

Two cables system !






Regarding the fan issue, I plugged a fan into a mother header after rolling back to a previous BIOS : it seems to have solved the issue, no fan spinning while the PC is off.
Or maybe the Vary riser was the problem.
 
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aquelito

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

Master of Cramming
Silver Supporter
May 18, 2016
546
281
I am thinking on making a small system for the road with a thin ITX board and the single slot RX 460 I already have. I am thinking on using the Petit PT13 case, https://www.aliexpress.com/item/60c...-USB-3-0-Extender-Cable-with/32737732873.html this powered x1 riser powered by http://www.ledgroupbuy.com/12v-5a-power-supply-w-4pin-molex-connector/ this and an ordinary molex-to-floppy converter. 60W is not 75W but I will eat my hat if the RX 460 really consumes 75W. And I will undervolt the video card anyways :)

The biggest problem I have -- where do I find a pre made case for a single slot 170mm video card?
 
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CC Ricers

Shrink Way Wielder
Bronze Supporter
Nov 1, 2015
2,109
2,334
@aquelito, seeing that you are using a Kaby Lake Pentium with the H110 board, did you have to flash the BIOS to accept it, or did it work right out of the box?
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
@CC Ricers : I had to flash the BIOS first with a Skylake CPU I had.

I first tried with the latest bios, which made my system act kind of weird.
Then I rolled back to an older bios version - the first one accepting Kaby Lake - and it works just fine.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
948
1,116
This guy solved the issue of having the GPU constantly fed with 12V by adding a relay between the Meanwell PSU and the PCIe bus (does he mean slot ?), to provide +12V only when the system starts :

Normally, an ATX power supply would provide power to the supplemental connectors only at system startup, then switch off when the system powers off. Only problem is that my power supply stays on all the time. By adding a relay that triggers when power is provided by the PCI-E bus, the graphics card is switched on at the same time the rest of the system is. This relay also provides power to the PCI-E connector of the GTX 1060 via a modified PCI-E cable that isolates the motherboard's 12V rail from the 12V coming from the power supply.

Anyone more knowledgable could please elaborate a bit more and maybe propose an electronic diagralm to build it ?
 
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aquelito

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

We have been working on a 4X to 16X powered riser, with an integrated load switch !
Some units are for sale here if you are interested.