i'm trying to find the sapphire hd 4870 1GB or the 4890, both are so hard to find in canada ( newegg.ca , tigerdirect.ca ) and local store, I only found the 4870 512MB version. So I'm wondering if the brand is important ? The main reason I'm taking the Sapphire over another is because I've read so many thread with people using the Sapphire and its works flawlessly or almost. Or maybe should I go with a Nvidia but which one ?