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Making a US$68 ThunderboltEXII PCIe based TB2 eGPU adapter <-- doesn't work

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juniordiscart wrote here:

juniordiscart said:
Hey guys

I recently got very interested in eGPU projects, and maybe would start one in the near future, and preferably a Thunderbolt one.

Now, it seems like Intel is refusing to certify products like the Silverstone T004 and BPlus TH05 which would make all of our lives a little bit easier.

I was wondering however, whether the following suggestion would be feasible to implement by BPlus (as I understand correctly, they cooperate with this community to make eGPU happen) and as a Thunderbolt eGPU solution as a whole:

Let BPlus design a circuitboard like they do now with, but instead of one PCIe slot, a second PCIe slot that could be used to plug in something like this: Thunderbolt PCIe card

This way, they don't have to certify anything by Intel, and we get to buy a "cheap" add-in card.

Would this kind of thing work? When plugging a Thunderbolt laptop into the port, would it recognize that there is GPU running next to it?

Just an idea I'm throwing around, and sorry if this came by before. :beguiled: I'd like to test this myself, but I have neither the equipment, the time or money to invest in this right now.

Cheers!

A female-female pci-e extender/riser could give us the cheapest TB2 eGPU solution to date

You raise an interesting point. Yes, if managed to find a gender converter that converts the male end of the US$68 Asus Thunderbolt II EX into a female pci-e slot, then in theory it could be used for eGPU purposes. I say in theory because I'm not discounting Intel adding undisclosed extra interface logic needed to prevent us from doing that.

You'd need effectively the same thing as a PCIe riser but with two female pci-e slot ends: PCIe riser | eBay . Juniordiscart suggested a few posts down (here), a maxexpansion product to do this:

<A HREF="http://www.techpowerup.com/img/14-01-28/116a.jpg"><IMG height=281 src="http://www.techpowerup.com/img/14-01-28/116a.jpg"></A>plus-sign.png<A HREF="http://maxexpansion.com/backplanes/184"><img height=400 src=http://maxexpansion.com/sites/default/files/styles/uc_product_full/public/field/product/BP-star.png></A>

Ideal being to extend the x4 pci-e lines from the ThunderboltII EX to a PCIe slot that can host your eGPU. Then just give provide the adapter a 12V/75W input to drive the eGPU slot plus another (up to) 12V/75W to drive the ThunderboltII EX card, plus whatever external pci-e power your eGPU requires.

If you're handy with the soldering iron then could even make one by buying two standard x4-x16 pci-e risers, take off the pcie male end off one and replace it with the female end from the other.

If you want to try it then recommend securing one of the Asus adapters quickly. Doing such workarounds and circumventing Intel's TB distribution chain of Sonnet/OWC/Magna could see them pull such devices off the market. We saw that happen with the BPlus TH05.

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One thing that worries me is the Thunderbolt Header on the top of the card that should be connected to an Asus Motherboard.

I'll try to send an e-mail to Asus to ask what the exact function of the header is.

post-26812-14494997770725_thumb.jpg

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One thing that worries me is the Thunderbolt Header on the top of the card that should be connected to an Asus Motherboard.

I'll try to send an e-mail to Asus to ask what the exact function of the header is.

according to ASUS ThunderboltEX II Add-on Thunderbolt 20 Gbps Cards Now Available | techPowerUp,

a special header that's used for timing, and low-level system interface
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So, if I get this right, we have an Asus card with a Thunderbolt chipset as output and socketed as a PCI-Express for input. Still, why are you guys so sure that it works in both ways?

Sent from my iPhone using Tapatalk

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So, if I get this right, we have an Asus card with a Thunderbolt chipset as output and socketed as a PCI-Express for input. Still, why are you guys so sure that it works in both ways?

We're not sure it works. However, we now know the main systemboard in the Sonnet Echo Express SEL (and probably earlier Echo Express SE) can act as mating female-female pci-e extender to test one of these Asus cards. See http://forum.techinferno.com/diy-e-gpu-projects/6918-updated-2013-13-15-macbook-pro-thunderbolt-2-egpu-plug-play-optimus.html#post95140 . Anybody with the right Sonnet hardware + TB notebook willing to try?

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Just to make this thread a bit more complete:

I have sent an e-mail to ASUS support, still waiting for a reply though. I also found that the HP Thunderbolt expansion cards (they are not listed on the certified Thunderbolt Products list by Intel, but can be bought on Amazon) also have a similar header. The HP website also mentions they are only usable on certain motherboards. So it could indeed be a whitelisting mechanism, or as prizm3d linked, that it is used for timing and low-level system calls.
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This sounds very interesting!

Since PCI-E and Thunderbolt are both two-directional communications, this should be possible.

I think the transmitting and receiving pairs need to be swapped so that the the ASUS card and a graphic card can talk to each other.

And then, I come up with some questions.

What would provide the clock? If no one is providing, do i need an external clock? If so, what frequency? (I found 2.5GHz for PCIE 1.0, is that the same for 2.x?)

What about the SMBus and JTAG in the PCIE pinout? What should I deal with them? May also swap the Tx / Rx of JTAG? What about SMBus?

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It seems I can't get any response from ASUS about the TB_HEADER cable. :(

I dug some more and I came by this webshop: MaxExpansion. They sell PCIe backplanes with ATX powersupply connectivity. It are the same circuit boards used in their CUBE enclosure series which can be configured with a Thunderbolt option. I think they may be a better option than purchasing an EXP GDC or BPlus PE4C V2.0 along with a PCIe riser as suggested in my quote by Nando in the first post.

Maybe their PCIe backplane that is in closeout sale could be quick test bed for someone willing to cheaply try out the ASUS ThunderboltExII.

They also used to sell their Thunderbolt PCIe add-in card separately, but they and their resellers took them all down. :/ This would have been ideal for a Thunderbolt-only setup.

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It seems I can't get any response from ASUS about the TB_HEADER cable. :(

I dug some more and I came by this webshop: MaxExpansion. They sell PCIe backplanes with ATX powersupply connectivity. It are the same circuit boards used in their CUBE enclosure series which can be configured with a Thunderbolt option. I think they may be a better option than purchasing an EXP GDC or BPlus PE4C V2.0 along with a PCIe riser as suggested in my quote by Nando in the first post.

Maybe their PCIe backplane that is in closeout sale could be quick test bed for someone willing to cheaply try out the ASUS ThunderboltExII.

They also used to sell their Thunderbolt PCIe add-in card separately, but they and their resellers took them all down. :/ This would have been ideal for a Thunderbolt-only setup.

Great find there with the maxexpansion PCIe backplane product. I've updated the first post pointing to it as the suitable product to test with the Asus ThunderboltEX II. I also found info about the Thunderbolt adapter kit they used to sell on web.archive.org : Thunderbolt Expansion Kit | MaxExpansion.com. Numerous backplane options were available to the customer. Looks like they may have rolled that product into their microCube/nanoCube enclosure offering:

http://maxexpansion.com.tw/desktop/micro-CUBE-thunderbolt-pcie-expansion

http://maxexpansion.com.tw/desktop/nanoCUBE-thunderbolt-pcie-expansion

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If these PCIe expansion backplanes are compatible with current Thunderbolt-PCIe 3.0 cards, will they be "hunted down" due to licensing problems with Intel?

If not, then we should really get Bplus Technology to consider making this. It's a very portable and better solution than the current Thunderbolt eGPU setups.

Best of all, we won't be needing a PCIe 4.0 version since Thunderbolt-3@40GT/s will already have enough bandwidth for 100% GPU performance.

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If these PCIe expansion backplanes are compatible with current Thunderbolt-PCIe 3.0 cards, will they be "hunted down" due to licensing problems with Intel?

If not, then we should really get Bplus Technology to consider making this. It's a very portable and better solution than the current Thunderbolt eGPU setups.

Best of all, we won't be needing a PCIe 4.0 version since Thunderbolt-3@40GT/s will already have enough bandwidth for 100% GPU performance.

I agree. The Asus ThunderboltII EX + maxexpansion backplane would be better for eGPU purposes. That's because the budget Thunderbolt enclosures come with piddly power supplies and often only support single width x4/x8 cards. This alternate solutions have no chassis or power limits that not only add cost, but have to be removed or worked around using a pcie riser/extender to give us a x16 slot.

The only hitch here is that unknown Asus header. We are not sure if it's necessary to wire that up or not. Only way to confirm if this will work or not is for someone with a TB cable and TB notebook to buy those two parts, connect them up, add a video card and see if it works. Would be great if it works.

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Hello, i am new here, actually this is my first post. I used to have had a x230 + bplus technology pcie to express card + 770 gtx and it was a very nice experiment, and worked quite well for my needs. After reading the macbook + 780ti post and seeing the video, i was tempted to get a new macbook for myself (got the late 2013 standard retina 15) and try out a similar solution. This being the case i am a bit out of $ to complete my new egpu, and started to look over alternatives (europe is overpriced by a margin unfortunately).

As so i got all excited when i saw this topic, and started to look around for the described asus part. In reality asus are not the only to make this kind of expansion boards, HP has one also with the expected premium http://www8.hp.com/us/en/products/iss-adapters/product-detail.html?oid=6254963#!tab=features and of course they use a tb_header also, as specified by Intel here: Intel announces. In reality the little port is a GPIO interface, and it as any other interface is programmable (for linux kernel documentation on GPIO https://www.kernel.org/doc/Documentation/gpio/gpio.txt). Now the actual thing is i can't figure out what could the 2 companies have done with the given GPIO, and how safe is to assume one could undo/redo the given setup (sorry if I seem overwhelmed by the GPIO stuff, i am a web developer, and as such have no extensive knowledge of system/kernel/driver development). Maybe Tech Inferno Fan or someone else with a few more ideas and knowledge can make some sense out of this.

(on a personal side, i do not have the time to invest at the moment in this project, and for the time being neither the required $ for a pure test, otherwise i might just bought them and test what can I do with them in the current state things)

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After reviewing this thread, there are one major difference between thunderbolt on host and thunderbolt on target device as can be seen from OSS reply below -

Will your Thunderbolt target adapter PCIe card work directly in a 2010 Mac Pro and be able to successfully connect to a thunderbolt display?

Submitted by rruple on Wed, 06/12/2013 - 8:27am

Unfortunately, the Thunderbolt card we make only works as a target device. While it has a PCIe card edge connection it is a slightly custom pin-out and the device on the card is set in downstream mode. The Thunderbolt spec makes it difficult and costly to make a Thunderbolt certified host card. Many parameters of Thunderbolt are tied directly to motherboard resources that are not part of the PCIe slot. These include the requirement for Thunderbolt to support Display Port video and hot-swap of the cable through BIOS. At the minimum a Thunderbolt host interface would have to have a GPU, memory and a driver to support all of the Thunderbolt features built into motherboards. These additions to a host card would make it more expensive and over complicated for the functions most people require, which is a PCIe host interface using the Thunderbolt cable. Any host card that did not include the video and hot-swap could not be labeled as Thunderbolt compatible and violate our Thunderbolt agreements with Intel and Apple."

Therefore, it can be deduce that the asus card gpio is to detect the availability of the host motherboard. The main question is, can it be made to be the target?

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I have found those as well, but when you read the product description, it says:

This product is obsolete. Please contact us to discuss a suitable alternative.

So I doubt they sell them anymore. But I guess its worth a try to ask them about it if they still sell it, or have some reserve in stock.

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Actually from your link, it looks like it is not for display port, it is for GPIO.

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Although I see that it looks like it is for Display port, the picture is really just a schematic of what ports should be there. At the bottom-right, you can see the GPIO header, which is what worries us.

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More info on the ASUS TB2 GPIO card "The GPIO (General Purpose Input/Output) header is used to control the card power state, signalling and device hot plugging events to the motherboard’s BIOS."

So, in a client card, we don't need the capacity for "device hot plugging events to the motherboard’s BIOS."

That leave only two function and "signalling" capability I think might also be not needed.

What is the most important on the GPIO is the card power state controller (to wake up the card) a jumper should be sufficient.

Taken from wiki "Input values can often be used as IRQs (typically for wakeup events)"

Well, all this are only theories unless proven in practical application. BTW I think that the appropriate ASUS mobo is needed to "prove check" the GPIO.

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Hi,

I spend some days now on reading on GPU and TB2toPCIe. Since I have to wait for my GPU-Card I did some knowledge enrichment reading and after all I pulled out both Cards from the Akitio Chassis and took a look on it.

As you can see the 4 PCIe 2.0 lanes from the PCIe/Powered Board are just forwarded to the TB2 based one but to the other side - so the pcie-board connector just acts like as a mirroring riser card for PCIe 4x (physical) <-> 16x (physical/4x electrical) by switching the sides from a to b (it is like an crossed patch cable - if you will) - I bet this is the point, why the maxexpansion TB2 cards won't work in a normal PCIe slot, since their pins are not mirrored.

I guess it is plausible since this port mirroring is needed because the host needs to talk to the target by connecting in a direct manner not in slaved one let's say - since it is just an extension :)

So - ahm - maybe I am stupid or it is just obvious and therefore not worth to be mentioned but why not just use that zillions of riser cards out there to do exactly the same by being slightly modified by doing this mirroring. So you actually could buy 2 PCIe riser cards and connect the slots in a direct way which means crosswise from the logical side?

As you can see the whole logic/intelligence is sitting on the TB2 board (btw same chips like maxexpansion TB2 expander card) - so if I am right ... well start to imagine yourself...

So to wrap it up, what actually just should need imho is tiny and cheap gender changer (like nando mentioned regarding the ASUS TBEX) and you are completely free by using the Akitio TB2 card, additionally put some molex connectors and the stuff for power stability (some cheap passives) to a small pcb beside a x4 and x16 PCIE slot and you are done ...

Regards

ME_

EDIT:

The only thing beside passives is of course the 12V to 3.3V Step Down Level converter and activation by SMCLK (B5) - and this is I guess the reason why things won't work by just connecting the TB2 Card to Power since this little BUG is doing the magic. You maybe can see one line going from B5 to the Bottom switching the sides by VIA and back to the Topside at the End is going to the EN pin of the BUG mentioned above. This is what enables the output of 3.3V to at least one middle Layer of the Akitio Board PCIe/Powered Board...

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I would suggest that you revise your methods of research/googling and reading the previous posts before you think that you have made an epiphany that others have not seen before. Because of hardware requirements a simple female-female riser would not cut it and an entirely new board would have to be fabricated. Even with that (and considering the TB ex uses one of the only bi directional TB core) the TBEX is only detected by the computer under specific circumstances and even then it is not directly possible to make an egpu. (I happen to have a TBEX2 and the custom board that I made for my egpu production project to be bi-directional). Even so we still have no clue about the function of the individual pins on the header (even if they seem to have little to no effect on detection and power) and If they might affect PCIe throughput.

Sry pretty sure I lost my train of thought somewhere in that but in short its not possible unless you have some inside information on the header or the inner workings of the multi layered board that is the TBEX. I am continuing to do some tests with possible fixes for this, if I make some headway I will probably have it replace the akitio daughterboard on my gpu solution (at least for the first run or until asus is forced to take it down).

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The "epiphany" you are referring to wasnt something that special. This past summer i spent a fair part of two months troubleshooting and "perfecting" my egpu setup on my mbp to a standard that i thought was near production build quality. (Nice case, nearly the size of the gpu, met all power requirements, etc) This involved creating a new mainboard as i was using the akitio's tb daughterboard. Since i was already paying to dry run my board i planned functionality for combining channels and using other cards such as ones for the bplus adapters or an x4 m.2 or usb 3 or anything else that comes out thus allowing me to use my egpu with my aspire s3 as well (has amazing mpcie placement). At one point in this process I had decided to see if there was possible interest in me selling my setup as a product (as i already had the neccecary contacts and pp setup completed to mass/batch produce). What i got out of it as you can see in that threads poll, is that those who didnt have an egpu or were having trouble, or wanted something that looked nice wanted mine, and all of the people who were fine with their messy setups (which i had for a while) said that they were content with the options available. Thus i tried the tbex adapter with my board to see if i could make my product more appealing by lowering the price. Since the tbex uses a multidirectional controller, it got detected by the laptop, however was not able to tunnel a gpu so i gave up.

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After that as you can probably see if you have been on these forums very long, i have been trying to make these forums more organized and easy to use/ get introduced to (with the help from nando of course). I have still been working on my product, i am just gearing it towards the community that would go twords the more expensive AIO enclosures that work out of the box such as video editors. I would still be offering the product at the same price ~60-100 for the main board which is still leagues lower than anything else comparable because even at that price i would make a worthwhile profit due to standard bulk pricing and deals with distributors because they were interested in my idea.

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