Autosave Lag on PC!

Hey guys,
i just encountered a problem when i’m running through the autosave points. whenever i do, my game freezes for about a pair of seconds. i already looked for help but nothing worked.
strange thing: on my laptop everything is just fine, although ist the same save and the same game.

Thanks for your help!

My PC:
Mainboard: Gigabyte GA-970A-D3
CPU: AMD FX-4170
GPU: Sapphire Radeon HD 6870
RAM: Kingston HyperX/DIMM 8 GB DDR3-1600 Kit
SSD: Samsung 840 Evo (250 GB) <- where Steam & Borderlands 2 is installed
HDD: Samsung Barracuda Green [ST2000DL004/HD204UI] (2TB)
Power Supply: SilverStone ST70F-ES 700W ATX22