Sudden Low FPS

[rafayet.hossain2004]

I buyed a new AMD GPU which is AMD Radeon HD 5450 Asus 1 GB Silent Edition.

When it Started :
In the last week I was Playing Multi Theft Auto Sanandrease 1.5 When I started the Multiplayer Game I got +50 FPS but after some days It became low (12-25) FPS. I checked my Internet Connection, but the connection was Good.

I have :
CPU : Intel Pentium E5700 3.00 Ghz
GPU : AMD Radeon HD 5450 Asus 1 GB Silent Edition
RAM : 4 GB DDR2 800Mhz
Windows 7 Ultimate 64 Bit

And the Games Recomended Requirements are :
CPU : Pentium III 1.00 Ghz
RAM : 512 MB
GPU : 64 MB Geforce 3 or better

But Why so low FPS, I have more specs that the Recommended.
Please Help me.

 

[rgd1101]

MERGED QUESTION
Question from rafayet.hossain2004 : "Sudden FPS Drop"

When i try to play games, it plays smoothly but suddenly my FPS falls to 0 and by screen goes off and come again, and a message is displayed, You Graphics Driver has stopped working and successfully recovered.

My Specs :
Intel Pentium E5700 3.00Ghz
3 GB Ram
AMD Radeon HD 5450 Asus 1 GB Silent Edition
and Windows 7 Ultimate 64 Bit

 

[rgd1101]

What are the cpu/gpu temp and usage during the game?