Using M.2 PCI-E lanes from NUC to communicate with external GPU

jb1

Limp Gawd
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Dec 27, 2014
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Hi all,
Given that the recent NUC M.2 ports use a PCI-E 3.0 x4 bus, do you think it would be possible to communicate with a GPU over them? I imagine pairing a NUC board with an external GPU this way could prove for some extremely small form factors! Any thoughts?
 

iFreilicht

[H]ard|Gawd
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I don't see a reason why it wouldn't work. PCIe 3.0 x4 definitely has enough bandwidth to handle a high-end GPU, QinX tested this with a Thin mITX board and a GTX970.
 

jb1

Limp Gawd
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Yeah I was curious if there was something complicated with the wiring, but take a look at this:

DSC06324.jpg


Something like that would probably do the trick. Not sure if I'll get around to trying this any time soon, but it could be a fun project.
 

Phuncz

2[H]4U
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Apr 12, 2009
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Hi all,
Given that the recent NUC M.2 ports use a PCI-E 3.0 x4 bus, do you think it would be possible to communicate with a GPU over them? I imagine pairing a NUC board with an external GPU this way could prove for some extremely small form factors! Any thoughts?
An external GPU will always be larger than the NUC itself. Maybe look into MXM cards laptops have ? It might even fit inside a NUC with support for a 2,5" drive: http://www.zentrica.com/product/amd-radeon-r9-m295x-mxm/
 

cennis

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is it possible to add a second gpu and run crossfire/sli on asus z97 impact through the m.2 slot then?
 

Bieberfever

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I already have the both the B and M key M.2 adapters from BPlus, an M.2 extender board a Galax GTX 970 OC Short Form (193mm), HDPlex 250 and all the other bells and whistles to do this build. I will be getting the new i7 NuC when it ships on May 10th and am in the process of having the case designed for this build. Will keep you guys up to date on progress etc. By my calculations the whole build should run under 2.0L running the 970.
 

jb1

Limp Gawd
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I already have the both the B and M key M.2 adapters from BPlus, an M.2 extender board a Galax GTX 970 OC Short Form (193mm), HDPlex 250 and all the other bells and whistles to do this build. I will be getting the new i7 NuC when it ships on May 10th and am in the process of having the case designed for this build. Will keep you guys up to date on progress etc. By my calculations the whole build should run under 2.0L running the 970.

Wow, very interested to see how this works as well!

is it possible to add a second gpu and run crossfire/sli on asus z97 impact through the m.2 slot then?

Also a really cool idea. These adapters look pretty cheap, so if you have another GPU laying it would be cool to try it!

EDIT: Don't motherboards have to have SLI/crossfire support built in to use this feature?
 
Last edited:

lvyelion

Limp Gawd
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Jul 2, 2009
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also need to consider the max power output of the M.2 port, as normal PCI-E do supply power to GPU
 

faugusztin

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also need to consider the max power output of the M.2 port, as normal PCI-E do supply power to GPU

That is why you have that white 3-pin connector there, that serves as a replacement for the power from M.2 slot. The M.2 slot itself is used only and only for PCI-E data (and maybe GND).
 

jb1

Limp Gawd
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I already have the both the B and M key M.2 adapters from BPlus, an M.2 extender board a Galax GTX 970 OC Short Form (193mm), HDPlex 250 and all the other bells and whistles to do this build. I will be getting the new i7 NuC when it ships on May 10th and am in the process of having the case designed for this build. Will keep you guys up to date on progress etc. By my calculations the whole build should run under 2.0L running the 970.

Would you mind sharing your case ideas for this build? I'd be really curious as to how you'll lay this out.
 

Erasmus354

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I kinda feel like this reading the thread:

eDUsFIx.jpg


By the time you go through all of this trouble you aren't really going to be saving much space if any from just using a mini-itx board.
 

jb1

Limp Gawd
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Haha, yeah.... maybe not the most practical project. However, If you put a NUC side by side with a half-height GTX 750/ti card you could I think you could get under 1.5 L. Pretty remarkable with a discrete GPU, right?

Also, the prospect of doing crossfire on an ITX board over M.2 sounds awesome. Imagine two R9 290X's stuffed into an M1 (using a normal mITX board). You could have one mounted on the very bottom pulling air in from below the case, and another mounted on the side. Crossfire in 12L! Also might double as an oven.
 

Siba

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Wouldn't a single 295x2 be similar performance without all the compromise and potential blown psu?
 

jb1

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Wouldn't a single 295x2 be similar performance without all the compromise and potential blown psu?

Yes, that might be true, but what about a single 295x2 coupled with another 290x for 3-way crossfire? You would power this through your normal power supply, not through the M.2 slot of course, so I don't think blowing out the PSU would be an issue.

Still this is definitely a thought experiment.
 

Siba

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290w for each 290x, 500w for a 295x2

The highest wattage you can get on an SFX psu is currently 600w. Even the single 295x2 does not allow much headroom for anything else
 

jb1

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290w for each 290x, 500w for a 295x2

The highest wattage you can get on an SFX psu is currently 600w. Even the single 295x2 does not allow much headroom for anything else

True, true. This might be crazy. However, there might be an interesting application for Crossfire in an ITX build down the road. Who knows? EDIT: For example, what about two 390x's when they're finally out?

You could probably do two of these:
http://www.amazon.com/Sapphire-Compact-PCI-Express-Graphics-11235-06-20G/dp/B00N2ROP36

But again, performance would be worse than a single 295x2
 

trugate

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I'd be interested in a gaming laptop-like pc in super small form factor, even if it ended up being like a NUC only in cube form... I was always interested in using a mini itx, micro atx psu (or similar) and using a pci-e x16 ribbon adapter to fold a gpu behind the motherboard, but never had much drive to do it. You could have the cpu hs/f flush with one side of the case, and the gpu fan intake flush on the other side, both pushing heat out the back (or maybe orient it to be top?).

This is probably why I don't have money.
 

Bieberfever

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I kinda feel like this reading the thread:

eDUsFIx.jpg


By the time you go through all of this trouble you aren't really going to be saving much space if any from just using a mini-itx board.

Can do this build under 2L with a 970 whereas the smallest reasonably available ITX build will be Dondan's A4 which is over twice the volume. If I can solve the problem of getting power to the PCI slot to power a short or low profile 750ti, then the volume would likely shrink to well under 1.5L (HDPlex 160 instead of 250).
 

rawrr

Gawd
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This is all really cool, but I think a major problem would be fabricating the case.
 

jb1

Limp Gawd
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Can do this build under 2L with a 970 whereas the smallest reasonably available ITX build will be Dondan's A4 which is over twice the volume. If I can solve the problem of getting power to the PCI slot to power a short or low profile 750ti, then the volume would likely shrink to well under 1.5L (HDPlex 160 instead of 250).

How about something like this?
TB2EnWqaXXXXXcMXXXXXXXXXXXX_%21%212106314686__85878_zoom.jpg


It isn't shielded which could be a problem.
 

Bieberfever

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What ideally like to is to create three versions of the case for short, medium and full length cards and sell kits.
 
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