Deus Ex: Human Revolution - Fantastic, retro game. Runs like crapola:

i5 CPU
4GB DDR III
ATI HD 6850
SSD
ASUS MB

Runs better in Direct X 11 but ALWAYS locks up (so unplayable)

Switch to Direct X 9 and it NEVER crashes but jerks around all over the shop.

Anyone got the silver bullet? Or a few tweak tips? Thanks