Is it possible for me to upgrade my graphic card on Optiplex GX620 SFF?

[akod55]

My specs are

Intel Pentium D CPU 3.00GHz 2.99GHZ
RAM 2.00GB
Intel 82945g chipset family.. I dont know if that needed

What i found is that upgrading my card to AMD Radeon HD 6570 or 5450 is way better and it will let me play my basic games like Garry's Mod, Minecraft and Dead 4 life 2

does that mean i need to upgrade my CPU or no ??

My power supply is 275 wat - do i have to upgrade this??

i just want to upgrade so i can play my favorite games

please help me here D: i am clueless

my desktop is Dell small factor (GX620)

thank you for reading.....

 

[laviniuc]

i don't think you can add a graphics card. no port for it on the board...

http://data.stuartconnections.com/object/image?p=10059&i=3

http://www.stuartconnections.com/de/motherboards/5762-Dell-Optiplex-GX620-USFF-Main-System-Mother-Board-with-Tray-MH415.html

 

[akod55]

i thought you can :O D:

what about this ????
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161418