Wait a minute, the game only has a poolsize of 140MB by default? My god, that would certainly explain why it struggles so much to load textures. And I'll copy/paste it here for ease of access:
Try this. Go to C:\Program Files (x86)\Steam\steamapps\common\BioShock Infinite\Engine\Config. Open BaseEngine. Find PoolSize and change the value to 512 or 1024 (Depending on how much Vram your card has). I run a GTX 660ti so im using 1024. Next search for MinSmoothedFrameRate and change it to 62. Right below that is MaxSmoothedFrameRate, change it to 122. Close and save changes. These tweaks gave me a massive performance boost and eliminated hiccups.
May thine...strength...help the world be mended http://i.imgur.com/HdBP0.jpg