I noticed a post on the support forum and can't post there but some people may have issues with running Minecraft with any AMD Radeon Graphics cards as they could be you may have yet to set Minecraft to high performance by right clicking your desktop and setting the file javaw to high performance. If you have an APU and a lone GPU then it will default to the APU which is not your high performance card. Hope this helps some.
Problems with running Minecraft on high performance AMD Radeon GPU's