GPU Thin Mini-ITX with discrete graphics card

[CC Ricers]

When used in mining rigs, the SATA power connector is connected directly to the PSU as the power source. In a thin Mini ITX setup, you normally don't have that option so I don't know if it's safe or even compatible to draw power from the one on the motherboard. I might be wrong but I think @iFreilicht said that the power is regulated on that connector so it may not be possible.

 

[jeshikat]

I found this connector which I have one of I believe for bitcoin mining. Data goes through USB and power comes from a Molex connector which they provide an adapter cable to SATA. I don't really know if using SATA power directly from the motherboard's power header is a good idea, though.

Why not a M.2 adapter?

And you're right, I seriously doubt the motherboard's SATA power connector is rated for 75W.

 

[CC Ricers]

An M.2 adapter like this one? And then just replace the SATA connector with molex..?

 

[jeshikat]

Sorry, I meant a M.2 to PCIe like I used for STX160.0: http://www.hwtools.net/ExtenderBoard/P4SM2.html

That way you can get at least 2.0 x4 if not 3.0 x4 instead of running over USB.

 

[CC Ricers]

Ah right, guess you can power it from there. Only requirement is that it needs a 2280 length slot, which not all boards have.

Would a mini PCIe adapter work just as well? 1x speed only though.

 

[jeshikat]

The end of that particular adapter can snap off, making it a 2260 card.

I think I've seen someone do a Mini PCIe to video card before, but like you said, it's only x1.

 

[Kmpkt]

The mPCIe cards are PCIe 1x at 2.0 I believe. If you want one for testing, please let me know. I went through an eGPU phase a couple years ago and have a bunch of these I'd part with for cost of shipping.

 

[iFreilicht]

I might be wrong but I think @iFreilicht said that the power is regulated on that connector so it may not be possible.

That is true. You can maybe hope for a 750 (non-Ti) to work with this kind of setup, but I wouldn't bet on it. Thin ITX boards, even if they allow for 12V input, do all the power conversion themselves, and the board designers expect you to connect a maximum of four 2.5" drives to the SATA connector, not a GPU.

But what you could do is connect a 12V external PSU that is strong enough to power everything to the board and then use the internal power connector for the GPU. Granted, I would only do that with a 75W GPU, and even then the barrel connector might not be strong enough for it to work.

 

[CC Ricers]

But what you could do is connect a 12V external PSU that is strong enough to power everything to the board and then use the internal power connector for the GPU. Granted, I would only do that with a 75W GPU, and even then the barrel connector might not be strong enough for it to work.

You mean using the 2-pin power connector that's in all the thin mini boards (or 4-pin in the case of the Gigabyte H110)? I'm only planning to use it with a GTX 1050/Ti so yeah I'm staying within the 75W limit. But with one 12v line on the internal connector the wire needs to handle at least 4.16 amps to supply the additional 50W of power.

 

[CXH4]

Has anyone continued with this little experiment? I've been looking at thin mini-itx boards such as this one that support 12v power bricks such as this one, that's what the site states but I'm unsure:

http://www.gigabyte.us/products/product-page.aspx?pid=5881#ov

I was wondering if it was possible to power something like a low profile 1050ti and a low wattage CPU with just a supported 12v power brick and motherboard (as well as whatever wire may be needed to provide additional power to the GPU)? I want to avoid the use of additional power supplies.

This is out of curiousity, I'm interested in potentially starting my own project around this idea.

 

[Kmpkt]

If you want to use an LP 1050ti, you're likely going to need some sort of powered riser to make that work. I'm pretty sure the x4 slot will be bound to 25W output as that is standard spec for PCIe x4. Alternatively you could get a full sized ITX card that has a power header onboard. The perfect candidate would be either a 1050ti that has a 6 pin connector (not sure if these exist) or a short 1060 like the EVGA.

 

[Sean Crees]

All the power connectors in a pci-e slot are in the x1 portion, the rest of the connector is just data contacts.

See here on page 53: http://read.pudn.com/downloads166/ebook/758109/PCI_Express_CEM_1.1.pdf

The only pins that have 12v power on them are pin 1, 2, 3 B side and pin 2, 3 A side. The pins with 3.3v are pin 8 B side and pin 9, 10 A side. All of which are contained within the x1 portion of every pci-e slot. You can pull 75 watts of power out of a x1 socket.

 

[CXH4]

If you want to use an LP 1050ti, you're likely going to need some sort of powered riser to make that work. I'm pretty sure the x4 slot will be bound to 25W output as that is standard spec for PCIe x4. Alternatively you could get a full sized ITX card that has a power header onboard. The perfect candidate would be either a 1050ti that has a 6 pin connector (not sure if these exist) or a short 1060 like the EVGA.

Thank you for the feedback! I just so happen to have the Zotac 1060, I could probably try that. The reason why I wanted to give the LP 1050ti a try, is that I want something thin like Lian-Li's PC-Q05, and if possible reduce the amount of length needed as opposed to having the slightly larger version. I really appreciate the advice, and thanks again!

 

[CXH4]

All the power connectors in a pci-e slot are in the x1 portion, the rest of the connector is just data contacts.

See here on page 53: http://read.pudn.com/downloads166/ebook/758109/PCI_Express_CEM_1.1.pdf

The only pins that have 12v power on them are pin 1, 2, 3 B side and pin 2, 3 A side. The pins with 3.3v are pin 8 B side and pin 9, 10 A side. All of which are contained within the x1 portion of every pci-e slot. You can pull 75 watts of power out of a x1 socket.

I'm not very knowledgeable when it comes to the power draw or data transfer of a component. I also looked at the page, and still have difficulty understanding. However, going by what I believe you are saying, I could power a 75 watt card just at the cost of bandwidth? I'm sorry if I am wrong, but I would like to know more about this. Thank you for the feedback!

 

[Sean Crees]

I'm not very knowledgeable when it comes to the power draw or data transfer of a component. I also looked at the page, and still have difficulty understanding. However, going by what I believe you are saying, I could power a 75 watt card just at the cost of bandwidth? I'm sorry if I am wrong, but I would like to know more about this. Thank you for the feedback!

Power delivery within the pci-e slot connectors are done within the x1 portion of every slot, regardless of total physical or electrical connection of the slot. Everything past x1 is just for additional bandwidth, and a card will auto negotiate its speed based on the electrical connection to the slot its put in. You can take an x4 slot, cut the plastic off the end so a physical x16 graphics card can fit into it and it'll work at x4 speeds.

 

[Kmpkt]

I thought there was a motherboard side limitation on X4 and x8 to 25W. If not, that is awesome.

 

[Sean Crees]

I thought there was a motherboard side limitation on X4 and x8 to 25W. If not, that is awesome.

So the official "rated" power for x1 and x4/x8 is 10w and 25w respectively, but the power pins are the same regardless. What does this mean? It means that its POSSIBLE a motherboard manufacturer MAY use smaller traces to those pin outs on a smaller physical pci-e connector because they technically only need a trace large enough to support 10-25w instead of 75w, and thus those traces may heat up excessively when more amps are drawn through them than was originally designed.

So if you are super worried about it, you might want to use some sort of heat detection device to verify the motherboard isn't getting excessively hot around the pci-e connector, or just point a fan at that part of the motherboard to make sure it receives adequate cooling. I'd wager most board makers just use the same width traces regardless.

 

[GuilleAcoustic]

PCIe-4x is limited to 25w, got that information directly from Asrock when I asked them this summer with the exact same idea in mind.

You'll need a powered riser, sorry.

 

[Sean Crees]

PCIe-4x is limited to 25w, got that information directly from Asrock when I asked them this summer with the exact same idea in mind.

You'll need a powered riser, sorry.

"Need" isn't exactly correct. "Recommended" is more applicable here. It is physically capable of giving 75w, its just not rated for 75w, and thus not recommended.

 

[GuilleAcoustic]

"Need" isn't exactly correct. "Recommended" is more applicable here. It is physically capable of giving 75w, its just not rated for 75w, and thus not recommended.

Got the information from Asrock who directlt asked their board designer ... Guess this is just the safest source.

But if you wanna play with fire .... Not sure that saying it will be OK is good advise when the manufacturer itself says it is not safe nor design for this.