I have the 256 and it works but when I put the 512 into the texture pack folder minecraft wont even run. i have tried optifine, allocating more RAM for minecraft, and using mcpatcher. I would really appreciate any help!
Your computer just cant handle the 512 texture.
I refuse to believe that is true because I know there is something I can do to make it at least run
Try install optifine or run Minecraft with more ram, there are a couple of guides out there how to do so.
Be sure to read the FAQ.
START java -Xmx4096M -Xms4096M -jar minecraft.exe
And install Optifine.
If it still don't work after that, try with version x256 and x128.
PureBDcraft - THE texture pack for a Comics-themed adventure in Minecraft!