Dell M6500 (and M6400) eGPU setup and limitations

If you are interested in using an eGPU (DIY ViDock) solution with a particular laptop, it can be REALLY hard to wade through 500+ pages of eGPU info over at the notebookreview forum! So, here are a couple brief excerpts to make things easier for Dell notebook owners.  Make sure to checkout the original thread pages (at the source links below) for more info!

DIY eGPU experiences - Page 549 [Dell M6400 info]

DIY eGPU experiences – Page 549 [Dell M6400 info]Source URL:

Relevant portion for M6400 owners…

I’m attempting to install an HD5750 (green) card into a Dell Precision M6400. This laptop has 12 gigs RAM and an NVIDIA Quadro FX 3700M (on board).

I’m into my 2nd week of attempts and can’t get passed the error 12. I’ve tried every combo of setup 1.x I can come up with.


Your system has TOLUD = 3.5GB (PCI BUS starts at E0000000), meaning there is no free 256MB pci-e space to accomodate a eGPU. You can only have a 3GB installation OR run the XP drivers (no DX10/11 or aero) where you disable the FX3700M. That would be a ‘dGPU off’ command in Setup 1.x’s startup.bat. You’d be booting blind until the HD5750 kicks in.

You are seeing the exact same issue as the Dell E43x0/E6x00/E6x10 folks have as described at. I’d suggest petition Dell to fix this as otherwise your expresscard has limited functionality.

Vostro/Latitide/Inspiron/Precision eGPU Info:

Including how to find out if you will have TOLUD issues:

REQ: bios mods to make Vostro/Latitude eGPU friendly

REQ: bios mods to make Vostro/Latitude eGPU friendlySource URL:’s Latitudes have been flagged as expresscard-equipped systems unable to do 4GB+ eGPU setups as described here. Which is a shame as the Vostro 3450 with a HD6630M dGPU is a…

[end for now]


  • Wow, that’s an odd issue. Something like this should not happen on a proper PCIe implementation. Things like these are supposed to be auto negotiated and the address width was supposed to be way over 32bit (PCIe was designed for post 32bit systems). Looks like Dell got lazy somewhere 🙁

    On a related note, is your internal Nvidia GPU on a MXM card? If so, you could try removing it, and see if there is suddenly enough address space on PCIe to accommodate the external GPU.

  • J.D.

    Agree 100% with you John, very sad and hopefully Dell will release BIOS updates to remedy the issue!

    It DOES have an MXM card so that’s actually a great suggestion you made.

    On a related frustrating note, NVIDIA Optimus (which can compress info to make a 1X connection much more usable) is only enabled for use between a NVIDIA card and Intel integrated graphics, not NVIDIA -> NVIDIA 🙁

  • Jean-Frederic Monod

    Thanks for this. Have these issues been addressed in the latest BIOS updates since ? I am contemplating trying this as I could use the upgrade and am currently on BIOAS A11. Is it worth it to install A12 ?

    • Hi Jean-Frederic,
      I am not sure if the issues have been addressed or not. Are you specifically wondering about for the M6400? If so I will not be of much help as I do not own that model. For affected model I am guessing that Dell has not fixed the issue, but hopefully I am wrong.

      I do have on my todo list to test eGPU with both a Precision M6500 and a Latitude E6430. I will be happy to test BIOS revisions for you at that point.

      In the meantime, best of luck to you if you go ahead and try it first! 🙂

      Best regards,

  • Niclas J

    Hi J.D.

    Any luck with the E6430?
    I’m also going to implement an eGPU for it.
    I saw that the TOLUD = 3.49GB with no “Large Memory” space, so I guess DSDT override is necessary.

    I’ve seen dynamic TOLUD on certain models like the Dell E6230 which automatically change from 3.49GB to 3.25GB whenever an eGPU is present. Source:

    Please tell me about your progress!

    • Hi Niclas,
      Thank you for your comment. 🙂 Unfortunately, I have now moved on to a Dell E5530 and I never tested the eGPU with the E6430 🙁 How about you Niclas, have you decided to make an attempt yet?

      Best regards and have a great weekend,

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