看影片很慢，應該升級顯卡還是CPU ?

很多年的HP Pavilion桌機，最近看影片有愈來愈慢的情況，請各位大大看一下:



CPU: AMD Phenom(tm) 9750 Quad-Core Processor
Memoey: 4GB
OS: Windows 7 32-bit
顯卡: 主機板內建 nVidia GeForce 9100
Gaming graphics: 1663 MB Total available graphics memory
Display adapter type NVIDIA GeForce 9100
Total available graphics memory 1663 MB
Dedicated graphics memory 256 MB
Dedicated system memory 0 MB
Shared system memory 1407 MB
Display adapter driver version 9.18.13.2049
Primary monitor resolution 1280x1024
DirectX version DirectX 10

如果買像這種便宜的獨立顯卡:
Nvidia GeForce 3 ti200 PRO 128MB

這樣看1080P或BluRay的影片，會有改善嗎?
還是要更快的???