i bought a computer. It said it came with an ATI HD 5450, but it didn't.
Take it back to the store & they offer to install an 5550 cause they don't have a 5450.
I know that the computer says it has a DDR3 RAM & the graphics card was supposed to be (the 5450) a DDR3 bus.
The 5550 graphics card is a DDR2.
Will the 5550 DDR2 graphics card be compatible with the RAM DDR3?
Will it cause problems?
Is the 5550 DDR2 slower than the 5450 DDR3?
any other things I should know / consider?
The memory on the video card is completely separate from the system memory. It does not need to match. That being said, the 5550 is a few tiers above the 5450 in the Graphics Card Hierarchy Chart, located here.