I looked into putting a 1.7 Banias into a M505x. Anyway I'll tell you that it is just a major pain in the butt to get to the CPU. The Heatsync is as such were you have to remove the LCD, keyboard, and the top of the main computer assembly to remove it. I can do it but it got quite anoying so I gave up on it and sold the CPU. It should be possible Donthan fyi is pin compatable and bus speed is the same. Also Donthan SHOULD work on the chipset but of course I don't know of anyone who has done it.