THIEF(2014) stars to lag after few mins

[c00lrajat]

Hi Guys
I recently installed the new Thief on my computer and when play the after some the starts to lag and the FPS drop down from 30 to just 7 or 8 and really need help on this so please help me
My computer Specs are
OS-win 7 64 bit
processor-intel i5-2320 3.00ghz
Ram-4gb
graphic card-Nvidia Geforce GT 520 Zotac edition

I have tried many things to improve my fps. I even overclocked my graphic card using Msi Afterburner and i even use razor game booster so please help

 

[sanderzz]

That graphics card wouldn't be able to handle Thief even on the lowest settings. Try lowering your resolution or getting a new graphics card.

 

[c00lrajat]

I have tried to play it on low resolution like 800X600 i even tried to play it on 720x480 but still it runs with lag for a few mins and after that it starts to lag and not only thief it also happens to splinter cell blacklist

 

[sanderzz]

It's definately your graphics card hitting a wall I think.

 

[c00lrajat]

I know that my graphics card is old but still how come when play it runs without any lag for a min or 2 then it starts to lag