Update: i have add 3 possible solutions for the Framerate Drops.
Note: Please remember this are unofficial fix made just by gamers/fans of this fantastic game.



Go to the Windows Start Menu and type: "regedit"

Find this folders:
HKEY_CURRENT_USER
Software
Eidos
Deus Ex: HRDC and locate at the right this line -> AllowJobStealing
-double click and set to 0

Now find this other folder:

HKEY_CURRENT_USER
Software
Eidos
Deus Ex: HRDC
Graphics locate the line AtiForceFetch4
-double click and set to 0

Start your game!! and enjoy the smooth augmentation!!!!!

-----------------------------OTHERS SOLUTIONS---------------------

Alternative 2
Some users recommend to open the browser "Google Chrome" and run the game. That may also fix the problem.

Alternative 3 (for Directx 11 players, remember, this is an Unofficial fix, it may cause crash)

Tutorial: (NOTE: this may work only for Directx11 in Windows 7 x64, Nvidia 660ti)

Click Start Menu and type in "regedit.exe"
Go to HKEY_CURRENT_USER
Go to Software
Go to Eidos
Go to Deus Ex: HR
Find -> "D3D11_CREATE_DEVICE_PREVENT_INTERNAL_TH­READING_OPTIMIZATIONS" in the right.
Double Click in D3D11_CREATE_DEVICE_PREVENT_INTERNAL_TH­READING_OPTIMIZATIONS and change the number 0, to 1.

Last part is simple, just change that 0 to a 1, Accept.

Hope it works.