Hi, sorry for crying out for help straight away, but I'm getting quite desperate with my setup. Trying to get HD 5850 to work with HP4530s (no dGPU, Corei5 with HD3000, 8G RAM) through PE4C 2.1 with expresscard adapter. Things I've tried (in order of trying): DSDT override (according to official guide) outcome: got the .aml loaded (compiled with warnings, but no errors) and the PCI bus under "Large memory". Win7 seems to fail to assign eGPU to the large memory bus (still get error 12). DSDT override with 36bit compaction (tried out a few different combinations) Uninstalled the DSDT, tried the 32bitA compaction (works only if use "for all devices") outcome (for both): got over the error 12, installed the display driver. eGPU works until I try anything (as it feels) hardware-acceleration-related - even booting up with screen connected or trying to maximize a window (any graphics - of course) gives me the BSOD. I'm actually wondering if it might be the faulty GPU/PSU or I can try doing something with Win7 and Setup 1.x? Going to try finding a way to test the setup with a different PSU/GPU and/or test the existing 5850 on a different PC now.