Slink

Success! I acquired a 12V 10A AC adapter and the GTX 750 Ti now works perfectly with stable performance and no crashes. And I save on some desk space by forgoing the ATX PSU in favor of the 120 watt power brick. Thanks to TheDeathEffect and Tech Inferno Fan for your advice. While on the topic of insufficient power supplies, this experience with the 750 Ti now explains one issue that would occasionally occur while I was using the Radeon HD 6670 for my eGPU: Sometimes the external display would flicker for a few seconds, then show a blank screen while the game and audio continued playing. I always wondered why it happened, but now I know it was most likely a result of the anemic 24 watt AC adapter I was using before. The fact that I was able to use my previous setup for so long on that tiny 12V 2A adapter makes me even more impressed that the HD 6670 managed to work at all, and for extended periods of time. The power consumption on that thing must have been miniscule. My current setup is now a Lenovo ThinkPad X200 (P8600 Core2Duo @ 2.40 GHz, 4GB RAM running Windows 8.1 and using a DSDT override) connected via ExpressCard to a PE4L (SW1 = 1, SW2 = 2-3) holding an EVGA GTX 750 Ti SC powered by a 12V 10A AC adapter, outputting to a Compaq 1701 VGA monitor (max resolution 1280x1024). I could extend the desktop across the internal laptop display using the integrated 4500MHD graphics, but it's not practical given my limited desk space.

The card I'm using is an EVGA GTX 750 Ti Superclocked, which the EVGA website says should draw the same power as the normal 750 Ti. But could the factory overclock draw more power than the reference cards and go over the 72 watts my adapter is providing?

I did a clean install of Windows and the dsdt.aml file still works. I also acquired a 72 watt (12V, 6A) adapter for my GTX 750 Ti, but I still get hung up trying to start a game. Pre-rendered movies and cutscenes play fine, but as soon as I get to a menu or actual gameplay, my screen either goes blank, or throws up a blue or green screen after a second or two, and I'm forced to do a hard restart of my computer. I'm at a loss here; the most recent drivers are installed, no other conflicting drivers are present, Device Manager shows everything working fine, and the DSDT override seems to have allocated enough memory to eliminate error code 12. What else could be going wrong?

Thanks for the suggestion, I'll report back once I acquire a suitable power supply. One more potentially dumb question: When I wipe my hard drive and do a clean install of Windows, does anyone know if I can re-use the dsdt.aml file I made without any problems? Or will I have to go through the entire DSDT override process again from the beginning?

Partial success! I fixed the errors in my DSDT.dsl, performed the override, and allocated enough memory to run the GTX 750 Ti with 4GB RAM in my X200 on Windows 8.1. The only issue now is that when I try to launch a game, my computer crashes after all the intro movies and the GPU starts to kick in. It's fine for watching YouTube videos and videos on local storage, but anything intensive and I get a crash. My theory is the power supply; I'm currently using a 12V - 2A AC adapter for the PE4L, which was fine for the HD 6670 but may not be enough for the 750. Does anyone else have any thoughts on this?In case anyone else has trouble with the override, the errors in my DSDT.dsl were all "Invalid object type for reserved name ^ (_PLD: found Buffer, P ackage required)". I was able to fix them by finding these linesName (_PLD, ToPLD( PLD_Revision = 0x1, PLD_IgnoreColor = 0x1, PLD_Red = 0x0, ... PLD_VerticalOffset = 0x0, PLD_HorizontalOffset = 0x0) ) // _PLD: Physical Location of Device and changing them to thisName (_PLD, Package() { ToPLD ( PLD_Revision = 0x1, PLD_IgnoreColor = 0x1, PLD_Red = 0x0, ... PLD_VerticalOffset = 0x0, PLD_HorizontalOffset = 0x0)} ) // _PLD: Physical Location of Device

Thanks for replying, I am going to try the DSDT override again. I have a basic idea of why an override is needed, but I was hoping someone could help me understand why my particular eGPU setup was working with the HD 6670 (no override necessary) and won't work with the GTX 750 Ti. EDIT: Never mind, I found out why I've been getting Code 12 errors. According to Tech Inferno Fan, the GTX 750 requires 256MB+32MB of PCI space as opposed to the typical 128MB+32MB+16MB in other Nvidia cards. Even though my TOLUD = 3GB, that evidently isn't enough space to accommodate the 750. Wish I had known about that before purchasing a new card. I have no coding experience and haven't found anyone else with a Lenovo ThinkPad X200 who has done a DSDT override, so it looks like I'll be flying blind with this.

Hello, this is my first time posting so I will give some background on my setup. For the past 7-8 months I've been using a PE4L-EC060A (v2.1) to connect a Radeon HD 6670 to my Lenovo ThinkPad x200 via the expresscard slot, no external power supply needed. This worked perfectly as a plug-and-play eGPU on both Windows 7 and Windows 8.1 (big thanks to Tech Inferno Fan and all of the users who have posted in this thread for guiding me towards that setup). I recently purchased an EVGA GTX 750 Ti to use for my setup, which is detected by Windows Device Manager in Windows 8.1 and allows installation of the latest Nvidia drivers 347.52. However, WDM shows the error Code 12 for lack of resources for the GTX 750 Ti. I tried and failed to do a DSDT override, causing a BSOD loop upon boot. I used a system restore and have tried booting with only 2GB of my 4GB RAM. This allows the card to work and output to an external display, but crashes soon after launching into a game, alongside the laptop's slower performance. I am planning on wiping my hard drive and doing a clean install of W8.1, but would like to see if there's anything else I can try before doing so. I'm trying to understand why the Code 12 error appears for the GTX 750 Ti when everything worked fine for the HD 6670. My TOLUD = 3GB, so I should have enough PCI room to play with for an eGPU. But I'm assuming that because the card I'm attempting to use is a GTX 750, it "requires over 256MB contiguous space" and thus requires the DSDT override. What is it about the GTX 750 Ti vs. the HD 6670 that makes it unusable with my current setup? Does it have anything to do with the GPUs' vram (2GB DDR5 vs. 1GB DDR3?). Or is it simply the newer technology with higher requirements? And does this mean I will have to find some way to make the DSDT override work if I want to use the newer GPU?