It will run it , but it won't be great, you will have to run it on lower settings, are you thinking of upgrading your gpu?
Skyrim is pretty CPU stressful, and a good CPU with a good GPU will be able to run it.
I've seen gameplay with an 1100T X6 and an HD 4870 1GB @ 1080p with a mix of settings. Around 30 to 50FPS. I don't think the 512MB will be able to handle it (I believe Skyrim uses around 700 to 1GB of VRAM) as well. Cannot tell for sure unless you try it.