I have a Thinkpad X220 with an I5-2520M and 16GB of RAM. I purchased a PE4L 2.1 from HIT about t 2 months ago along with a used GTX 460- running @ x1.2opt I've been experiencing some problems (BSOD, constant driver crashes, extremely sluggish frame rates w/ internal screen, disappearing mouse cursor w/ external screens) and have (I think) narrowed it down to the GTX 460. I have tried out two other video cards, an 8800GTS 320mb and a 4850 1GB, and they appear to work fine, w/o any driver crashes or BSOD. I am wondering if I would be able to run an AMD HD7850 2gb with my laptop. I am aware of the requirement of a 256mb memory space to run AMD cards- however, I noticed in one of the test configuration reports from NANDO ( http://forum.techinferno.com/diy-e-gpu-projects/2747-12-5-dell-e6230-gtx660%40x1-2opt-hd7870%40x1-2-pe4l-ec060a-2-1b.html#post37197 ) that the Dell E6230 was able to run it without resorting to any ACPI modifications to move the egpu memory allocations to 36-bit space. Would I be able to reliably run the HD7850 2gb with the X220 w/ 16GB RAM?