Between the two, which is the better buy. XFX Radeon HD 5770 Video Card - 1GB GDDR5, PCI-Express 2.0, CrossFireX Ready, or the XFX Radeon HD 4890 Video Card - 1024MB DDR5, PCI Express 2.0 x16, CrossFireX Ready. I am open for suggestion on the purchase of a video card in the less than $200.00 range.