Let's figure out how to convert internal MXM connector an external PCI-E x16 box

There's a complete power supply circuit on each MXM board, a quite complex one for the GPU and a smaller one for the VRAM, just as on desktop GPUs.

The most difficult part would be to convert the display signal of the GPU to an LVDS signal.

This can't work for several reasons, e.g. I'm pretty sure a 3.0 VBIOS can't parse the MXM 2.1 structure stored in the system BIOS.

 

I was curious about this too. A 9800M per example can be flashed with a 280M MXM 3.0 vBIOS though.

 

Really? Ok, that's interesting. If I think about it again it also makes some sense, if it wasn't possible at all, MXM 3.0 could not be backwards compatible at all, but it only says the modules aren't required to be backwards compatible. So the MXM 2.1 calls and functions might still be in some 3.0 vbios.

 

Yes.
Wish I could tell you more, svl, but my knowledge in this field is limited and only based on experience

 

Without the MXM 3.0 specifications/papers the display signal would most likely be better understood through reverse engineering (MSI-GS45-M or laptop). That is to map out the signal, and see if post processing is required or is already accomplished. If post processing is required, then it should be rather easy to find a 3rd party IC/PCBs that accomplish that, but then again signal specifications would need to match. I think the 6990M has a side connector, I believe its for display, if I had one, I would use a logic analyzer to understand the output/input signals.

I looked more closely at hi-res recent MXM boards (6990M), you were right, so there is a discrete VRM, that's interesting I though they were "auxiliary ICs" and power filters for the GPU, I skimmed through them. That basically means the voltage/impedance must be matched at the connector (though papers are not available). This means probably an external power circuit would be needed regardless to match the wattage if one is building PCI-E to MXM or MXM to PCI-E.

 

Most notebooks have are internally connected per LVDS (or more precisely FDP-Link), desktop cards won't deliver you a signal in this form, so in order to get a signal on the internal screen it'd be necessary to transform it into an LVDS signal.

It's a Cross-Fire connector, required in order to run two GPUs in the same system.

Desktop GPUs get most of the power they need through a separate connector, not via the PCI-E connector, so it'd probably be enough to simply have the necessary PSU for the desktop card.

 

Have you by any chance proceeded to build such a project to connect a mobile graphics card into a desktop setup, or a desktop graphics card to a laptop? (mxm to pcie-e might be a little irrelevant, given that similar solutions exist already, yet you probably already know).

I looked into the possibility of plugging a mxm card into a desktop setup some time back (probably not worth it because of the card's price), but it only stayed on the drawing board. By attempting to replicate the layout of the power circuit, and laptop display circuit layout, so that they were quite analogous to a desktop card.

 

there's already products on the market that convert MXM to pci-e. not vice versa unfortunately.

 

So this project is dead?

 

Soo do you have another link to this riser card.....I am halfway temped to try this....would this riser card work on a ASUS G51j because I thought they use their own special mxm boards too be a pain in the butt. I am really interested in trying this.

EDIT: so if you don't care about the internal monitor to work this isn't that difficult right? It sounds like the hardest thing is to get your internal monitor to work.

EDIT: PCI express mini is only 1x right just like an express card slot?

 

is there already way to have some sort of vidock mxm to pcie for mxm 2.1? I see comment saying it would be easier to make for mxm 2.1.

Personally i'd like to make an mxm 2.1 riser ribbon cable, so i can mount a full sized mxm 2.1 TYPE III on to the bottom of my laptop(MXM 2.1 TYPE II) with custom heat sink.

Is there already a vidock type of mxm 2.1 to pcie already? I see people mentioning it would be easier to do with mxm 2.1.

Personally I want an MXM 2.1 riser ribbon cable, so i can mount a full sized mxm 2.1 TPYE III on to the bottom of my laptop(MXM 2.1 TYPE II) with custom heat sink and fan.

 

there isn't. just check previous posts. there's no mxm to pci-e converters available and no one will do it. for you to make it yourself it's very difficult.

 

not from 2010 on the don't...my hp dv7 has no pci card slot

 

also expresscard delivers a very crappy performance.

 

vidock got show down for thunder bolt because thats is just stupid talk.

ViDock "Thunderbolt War?"

 

Whoa, If I read this 8 months earlier, I might have chosen this as my 4th year design project topic...

 

Came across this thread when looking at options for an eGPU as I have an mxm2.1 slot which has the potential to be a pcie slot with 16 lanes (blowing any issues with bottlenecks out the window). So I had quite a different application in mind to some when I looked at this - mainly using the mxm2.1 to run an external graphics card (outside of the laptop entirely and powered by an external ATX psu) and then using that to run an external display.

There was a mention a few pages back to upload a picture of mxm2.1 v.s. pcie pinouts, which I've attached to this post (although at quite low res). And after looking at this I think I'll give attempting a mxm2.1 to pciex16 connector a miss as although it appears all 16 lanes could be connected quite easily (i've colour coded the corresponding ones) connecting the crazy amount of display connectors from the mxm card (pins 140-242) would be beyond my ability.

If I could just use the relevant pins from the mxm2.1 card to provide a x16 pcie connection (including random clock pins etc.) and connect them to a pcie riser and then plug those into a desktop gpu then I would definitely consider it.

Also another concern is I cannot find the relevant set of pins on the mxm2.1 spec for the first 11 pins of the pcie x16 spec. The majority of these are power (which would be supplied by an external ATX supply) but SMCLK, TD0 etc are nowhere to be found.

With this in mind I wont give it a try (for now) and instead attempt a x2 (or maybe even x4) link using expresscard 1.0 and all of my mpcie slots inside my laptop and a pe4h. Perhaps when I can afford a replacement laptop I would consider it.



Above mxm2.1 pinout (left) in comparison to pcie x16 pinout (right) with data lanes colour coded.

 

Awesome! REP!

 

WOW that is nice!
but there's a problem unfortunately. I don't think you can connect it just by matching the same pinout. you need somekind of converter.
but you should attempt. you don't need to physically mod the notebook. you can do it on the pci-e riser.

 

I've had another look into this and its looking more and more possible. I am planning on building my own pcie x1 passive adapter from the expresscard slot over the summer similar to this ( http://forum.notebookreview.com/8356280-post8754.html) as a cheaper alternative for an eGPU's than using a peal/peah.

@ __-_-_-___:
Thanks very much .
I think all that may be required is a passive adapter, the voltage level used in the lanes appears to be the same in MXM and PCIe. (I've attached a picture of a PCIe-MXM 2.1 adapter where there the pins for each lane are directly connected).






Also, sonny_mv's expresscard-pciex1 adapter demonstrates that a graphics card will run happily without any JTAG connections (pins 5A,6A,7A,8A and 9B on a PCIe connector).

As the voltage levels are the same, and theres no need for any of the JTAG connectors, all that may be required is to run wires between the transmitter-reciever pairs, the reference clocks (133&135 on MXM 2.1 to 13A&14A on PCIe) and the SMD data and clock pins (145&147 on MXM 2.1 to 5A&6A on PCIe). Then connect all power slots for PCIe to an ATX power supply.

I've contacted MXM-UPGRADE to see if they have any blank male mxm 2.1 boards/slots/connectors and will try and give this a go before September (When I'm starting a new job so may not have time) and I'll pick up a cheap pcie riser from ebay.

I'll hopefully put together a (basic) wiring diagram over the weekend.

Thanks!

 

that would be so great. it would eliminate any bottleneck of current and future thunderbolt solutions.
it's a compromise if you want mobility you need to get a dual gpu notebook.

 

This is what I have been thinking all along. If someone would just make a unit that would plug into my MXM slot and run a cable outside my laptop to a full size PCI-e x16 slot, then I would think that we could all run stuff on our internal displays and have a freakin' amazing GPU without any bottlenecks that are usually associated with e-GPU products.

Hell, I even have a heatsink for the aspire 6920 before I built my 6920(G) that doesn't split to go over to the video card. If this could be done then I could just use that and run my e-GPU off of my MXM type II slot.

I'M gonna be REALLY EXCITED if someone makes an adapter like this. It could be done for really cheap, so WHAT'S THE HOLDUP? I think that this could be really awesome for the people with switchable graphics as they could have a connector mounted on the outside of their laptop that would allow them to disconnect the external GPU when they wanted to be mobile and then reconnect it for all the graphics power they could want without any bottleneck.

 

despite this being very cool the truth is that thunderbolt x4 delivers an average of 95% of the gpu performance. worst cases 85%. best cases 100%. and it's way more convinient then this mods.
what I remembered was to make a mxm to thunderbolt adapter. there's already pci-e to thunderbolt adapters so why not.

 

i found this thread looking for a similar idea but for an igpu instead, way i see it is if tha intergrated gpu can communicate with pcie lanes then its completely possible to desolder/clean and recreate a connection to the x16 then pass that onto an external gpu. im working quite abit atm but ive got friends in handy places im going to chat to about this. sadly for me its guna take some expensive custom rig but mxm slot isnt that hard to accomplish. i shall document my findings and post them here. ive got an old acer 7741g which im going to use a test subject. i liked the idea of using an already present connection to do all the hard work aka the hdmi port but after evaluating the task im unsure it can handle the task which is needed, seems like a custom board on a miniture scale is going to be needed in my test subject but i got money to blow and really just wanna see this work

 

Chr15g, I was curious if you had made any progress. I own a sager NP8690 and would like to attempt the same thing as you. If I was able to just keep my laptop mobo and cpu while adding an external gpu it would save me a ton of money and allow me to put off an entire new build. So for my purposes portability is unnecessary. Hope you had some success, so that I may duplicate it.

 

Does anyone know of a card that you would be able to take your mobile gpu with an mxm connector and place it in a pci connector card to make it usable in a desktop. I'm mainly wondering because I have a spare one and would rather use it rather then buying another graphics card for my desktop.

 

BIOS support. Most laptops won't recognize any other cards than those ones that shipped with them.

 

bios is a minor issue. there are much bigger problems. like getting the correct specifications, making the schematics, testing, manufacturing etc. no one will make such a device. the ones that eventually could do it, don't want it to. also with the advent of thunderbolt it became redundant. you can get similar performances with already made products at a lower price without the need for any modding.

 

That we already know...

 

From building my own Mini PCIe to PCI x1 adapter, I can offer some advice that may be of use. As to why nobody has made a product yet, the MXM specification is released by MXM-SIG, which is under nVIDIA's control. They only release the documents to corporate customers apparently.

MXM is just a connector that uses PCIe verbatim (I suspect MXM 2 = PCIe 2.0, MXM 3 = PCIe 3.0).

The absolutely pins required are the following:
REFCLK+, REFCLK-, PWRGD, and the transmit/recieve differential pairs (i.e. HSOp(0), HSOn(0), HSIp(0), HSIp(0), HSOp(1) etc.)
So you really only need to hook up 3 + 4 x (number of lanes required) pins. For x1, that'd be 7 pins, for x16, that'd be 67 pins. I'm taking a guess, but you'd probably only need 4x or 8x for near-full speed.

You'll probably want to connect GND as well. Also, connect CLK_REQ# to ground as pulling it low is a request to start the REFCLK signal. Some laptops will require this.

Some matchups with PCIe -> MXM equivalents

REFCLK+ = PEX_REFCLK# (clock+)
REFCLK- = PEX_REFCLK (clock-)
PWRGD = PEX_RST# (PCIe reset)
PRSNT1# = PRSNT#1 (Hot plug detect)
PRSNT2# = PRSNT#2 (Hot plug detect)

HSOp(0) = PEX_TX0#
HSOn(0) = PEX_TX0
HSIp(0) = PEX_RX0#
HSIn(0) = PEX_RX0
etc.

SMB, and JTAG pins are NOT connected on a GPU so they are optional. The VGA, TV, DVI, HDA (High Definition Audio?), DP (DisplayPort) and SPDIF pins are not needed since these just route out to the corresponding laptop ports, which would be already present on the desktop GPU...
If you don't care for the internal monitor, you can also skip the LVDS pins. The DDCA pins, I'm not too sure about, but they appear to be optional as well.

The only contentious pin is RUNPWROK, this may or may not be needed, I can't tell without a MXM card or laptop.

I don't have an MXM-equipped laptop, otherwise, I'd be more than willing to whip up an adapter and schematic.

 

I haven't got an MXM laptop yet but this is definitely an alternative to the standard gaming laptop that I'd like to explore further. It'll be several months before I have one but I'd like to help out with this.

From what I understand of the MXM slot. MXM 3.0 is actually PCIe 2.0 and the new 3.1 version is PCIe 3.0. up to 16 GB/s of bandwidth in each direction provided. Enough to run at least 2 graphics cards and other expansion devices. More than 1 expansion card would require a PCIe switch though if the BIOS allows such a thing.

Regarding the LVDS for the internal LCD. Since desktop graphics card output via their external display output during normal operation. Perhaps running a line from the DVI out to an LVDS serializer before the MXM slot is worth considering. Or is tricking the switching software such as Optimus the only possible solution.

As for designing an adapter. There is 2 options.

1 - Manufacture the adapter yourself. May be extremely difficult due to small size of connector and tight tolerances required.

2 - Design a PCB using design software and produce a gerber (extended) file. There are companies that will produce a PCB from a gerber file. This might be very expensive, especially if any BGA chips are involved.

 

I think it's not that expensive. there's lots of companies and all they need is the file. the tricky part is to make the file, good luck with that....

 

Making the file would be pretty difficult. Luckily there is open source PCB design software available rather than software that costs more than 2 or 3 laptops.

First of all. A male MXM connector has to be designed from scratch since only MXM partners have access to reference gerber files. A connector such as female PCIe x16 would more than likely be part of a standard components library.

Designing the actual board is a different matter though. For a simple riser card, it is a matter of linking the respective lanes together and ensuring that each pathway for a PCIe lane is the same length. I'm unsure whether all the pathways have to be the same length or not. However since PCIe is a serial interface with multiple streams (each lane) used to increase bandwidth unlike a parallel interface such as PCI. I imagine it should be fine to a degree. If you want to use the internal lcd though, a simple riser card would likely not suffice. Instead an LVDS serializer would be needed. Likely to be a chip soldered to the board via perimeter connections or ball grid array. I reckon this could cause the cost of any PCB to shoot up.

There are other variables in designing PCBs such as number of layers, conductivity of solder and thickness of copper. However I'm not an electrical engineer so that should be fun.

 

Re internal LVDS, increasingly LVDS gives way to eDP and that's a lot easier to interface as it's just DisplayPort, same signals.

 

That is true, although the type of interface depends on the particular laptop model in question. This is the first I have heard of eDP myself.

Regarding my first post on this page though. Even if we can interface with the PCIe lanes within the MXM slot. There is one possible obstacle that could be difficult to get past. First of all MXM is more than a small PCIe slot with some display interfaces embedded in it. The installed module passes information to the host system bios on boot up which is then retained. I'm unsure what would occur without this information passed to the bios.

 

I've my doubts regarding the bios. because we have around mxm to pci-e cards that convert mxm signals to standard pci-e ones. we just don't have the opposite.

 

I pretty sure that MXM just uses standard PCIe signals in addition to it's own signals on other pins. If MXM didnt use standard signals then conversion would be required however the images of the MXM to PCIe cards that you are referring to show that lanes from the MXM interface are being routed directly to the PCIe slot without going through any chips or voltage regulation. That does imply that the signals are at least compatiable with each other.

While from those cards it does seem that the MXM cards are capable of interfacing with desktop systems that dont have any MXM components within the BIOS. I was referrring to the host system itself, in this case a laptop. It's possible that a system like that does need the MXM structure in order to initialize the gpu in question. I wouldnt put it past MXM-SiG to have such a requirement since MXM is a proprietary interface. In addition only certain GPUs work with certain laptops due to the BIOS (I'm aware that exceptions exists such P150HM with 7970M).

However as for why PCie to MXM cards dont exist. Its simply down to lack of demand and lack of incentive on the part of the manufacturers. The market isnt particularly interested in any innovation unless it is pushed by Intel (Ultrabooks etc) and certain other companies.

About the best solution I can come up with is removing the VGA card and the VGA cooling assembly. Then replacing that with a custom made PCB that fits into the MXM slot as well using the standard screw fastening points with an ePCIe x16 connector identical to the one in the profile picture above this post.

For an external PCIe implementation to work. A PCIe repeater is required before the cable interface in order to boost the signal as PCIe is only designed for a maximum range of 60cm approx. The other end of the connection would then connect via a similar configuration to an external PCIe box that has an ATX power supply as well as a PCB with a single x16 slot or two x16 slots wired as x8. This type of setup is already used to increase expansion capabilities of various professional systems but is very expensive.

Theoretically it maybe possible to use a PCIe switch to split the 16 lanes into multiple slots of varying bandwidths allowing for each card to have access to full bandwidth of the interface. Might be possible for Crossfire/SLi setups if the chipset of the host system supports it. HM77 supports mobile Crossfire/SLi making this a definite possibility.

 

It is true that MXM to PCI Express is not particularly difficult and an MXM module is closely matched to a regular GPU card, however there are some important differences:
nVidia MXM cards require the system to have an MXM System Information Structure (SIS) with information about what power consumption, connectors etc. the system has. AMD cards don't seem to care whether it is there or not, but this means either a custom system BIOS with the required SIS information, or an EEPROM on your carrier card with the correct image connected to the LVDS DDC pair (DPE) of the MXM card.

The other reason why this isn't readily available is that you have to purchase two cards in one, and MXM module and an MXM carrier. There is no market for this in the commercial space as it's just cheaper and easier to purchase a PCI Express graphics card.

The other comments about using a PCI Express bridge to divvy up lanes is all true and will work on any PCI Express lane, doesn't have to be 16 lanes, doesn't have to be the PEG interface etc.

FYI the MXM specifications are all online and freely available here:
http://www.mxm-sig.org/main.cfm?action=specifications

The SDK is controlled, which contains some more information on the MXM SIS, but if you google around you can find it.

 

I'm aware of the MXM to PCIe carriers cards for desktops, there are several companies out there that sell them for various versions of MXM. What i'm referring to is a module that goes into the MXM slot and carries the connections to a female PCIe x16 slot or an external PCIe cable connector. After that, a commericial backplane solution can be used provided that the laptop's connector is compliant with the external PCIe cable specifications. Those solutions aren't exactly cheap as they are designed for the professional market.

The MXM structure shouldn't be an issue as only the PCIe lanes and 1 display interface are being used. Of course which display interface is actually used depends on the host system.

Designing the internal MXM module is likely to be very difficult. The latest PCIe version has increased the operating frequeny to 8 GHz. As the frequency of a device increases, the signal dropoff and degredation issues become far harder to deal with. PCIe also has to be designed to a specific impedance on each lane. A four layer PCB is required with 2 layers for the PCIe lanes RX and TX pairs as well as 1 ground layer and another layer for power. Such a pcb would cost $100 or more to produce a time with several iterations likely to be required before a working version is made.

Other issues such as trace routing, crosstalk and reflection will also need to be addressed. Integration of the repeaters required to extend the PCIe signal range from it's usual 12 inches to a range suitable for cables will also need to be achieved. Such devices are configured via eeprom. Not an easy task but the result will be worth it.

Interestingly I recently found news that Haswell from Intel will be dropping support the legacy LVDS interface for notebook screens in favour of an eDP based interface (Displayport) which should make routing back to the internal LCD much easier. As far as i know Displayport and embedded Displayport are more or less compatiable. There are some changes for backlight controls with the eDP standard but the main electrical interface remains more or less the same.

As for the specs website. That website requires you to be a member of the MXM-SiG. Thought that required you to pay $3000 in registration fees, most of don't even spend that much on a rig.

 

how about to try a Kick starter with it see how many people will be interested

Mojo: Digital Design for the Hobbyist by Embedded Micro — Kickstarter

http://www.kickstarter.com/projects/545073874/bora-the-binary-explorer-board?ref=category

http://www.kickstarter.com/projects/kuy/galago-make-things-better?ref=category

http://www.kickstarter.com/projects...ny-arduino-enabled-usb-dev-board?ref=category

so it will be much cheaper if you will outsource it to some company
good money to be made also
i would buy it if it's under 150$

1000 people should not no be hard to find giving the opportunities it will bring

some stupid useless crap can gather couple hundred thousands dollars of funds easily there

even pure research projects gather there 10-80.000 $

i think this one would get great support

pcie x1 kit costs 100$

so lest say budget of 100 000- 150 000 $ for this project




maybe worth a try
and could start a really profitable business

 

One can petition a laptop manufacturer.

No need for conspiracy theories:

This is how it can be done:

A big company that is only into laptops and not desktops (so it's only profit to them) releases a GPU dock station that directly connects its X16 PCI-E from the the laptop mobo to the station.

Easy money. Imagine the flocking of people they will get. Now people will be able to have their laptops but when they set it up at home, a powerful GPU will be available.

 

And which that company would that be? I can't think of any of the major players that fit the description.
On second thought...Fujitsu, Toshiba, and Panasonic. At least I have never seen them market desktops.
Well, there are niche brands that exclusively sell laptops like Sager...but this could totally cannibalize their gaming laptop segment, who would want a GTX 680M when you can run a real GTX 680?

 

Ok, it looks like this forum topic is dead but i just picked up this project and im goning to try converting MXM 3 to PCI-E 3.0 x16. It might take a while to just find pinouts for the mxm 3 connector but once i do and im certain that its it i will probably post it here. And if this whole project works out i will make a new forum thread explaining how i went about it and how you can make your own. Wish me luck .

 

Good luck!

 

Alrighty, the official documentation on MXM 3 is unfortunately not available to the public but i still managed to gather most of the required documentation from all over the internet in order to make this thing to work.

These are pinouts for a Radeon HD7970M which is a MXM 3.0b card and was an option for my Clevo P150EM back in 2012. Just please bare in mind that these pinouts are for the card itself not the MXM connector. And also pinout description and voltage.

It looks like the MXM connector is 16x pcie 3.0 with a whole bunch of display connectors which just lead through the laptop the their respective ports.
And these are just simple and easy to find pinouts for PCI-Express v3 (x1 through x16).


"REFCLK+ = PEX_REFCLK# (clock+) HSOp(0) = PEX_TX0#
REFCLK- = PEX_REFCLK (clock-) HSOn(0) = PEX_TX0
PWRGD = PEX_RST# (PCIe reset) HSIp(0) = PEX_RX0#
PRSNT1# = PRSNT#1 (Hot plug detect) HSIn(0) = PEX_RX0
PRSNT2# = PRSNT#2 (Hot plug detect)
SMB, and JTAG pins are NOT connected on a GPU so they are optional."
crampedson posted this almost two years ago in this thread. Now i'v heard multiple times that JTAG and SMB pins are optional which makes this a bit easier

- (Originaly posted by chr15g)
And this adapter just shows that you can plug the Hs** and PEX_**** pins directly into one another.

The two biggest problems will be the power delivery to the PCI-Express connector and IF my bios doesnt recognise a gpu once plugged into the finished adapter, than the biggest problem will be making it recognise it as a thing plugged into the laptop. As for the connector power delivery, in a worst case scenario i could make another adapter for the pci-express 1x slot i have for my WI-FI card that would only connect to the power pins and than making it come together with the other adapter to power the card. obviously if this will work a powerful gpu will still need a PSU to supply power to it.
So far i have gathered most of the required information but for now im going have to pause the project (due to school) i will resume it during my Xmas break.

 

Right, i found a little bit of spare time and i found this MXM_spec_v301_°Ù¶ÈÎÄ¿â this is the official MXM 3.0 revision 1.0 Specification. This is exactly what we needed! If anyone could get a PDF version of this before it gets taken down, it would help out a lot. I know there is an option to download it somewhere, but i dont understand chinese or whatever it is and for some reason google isn't translating it for me. Thanks in advance! - WhackingCheese

Edit 1 : Nvm. got it on a school computer, this is certainly the MXM 3.0 A & B Electromechanical Specification PDF. Its got everything about the connector pins, ins, outs, sizes even some crazy diagrams which i hopefully wont have to worry about.

 

Could you please share with mediafire or similar service? Thank you!

 

Here: https://mega.co.nz/#!SsBDXbJS!rCTBmvgvLtpfKcl9LJFBx1coJntmvMAF8iPIyS15CA0
This is it.
I also mapped out the connector pins using the official pin output table. Left one goes on top of the right one.
(Image appears to be too big so i just put in a link.)
https://mega.co.nz/#!b0hmhIjQ!Pav8ICOhY0IgFPF4Sf40rB8lbzf9hjaVUTSfBa86gkI

 

Excellent work.

 

A custom type A card should be enough to route the signals outside of a laptop. No nood for big type B cards.