If you are using and AMD FW13, updating to the latest AMD driver will let you create a custom resolution (such as 1128x752) so you can game at lower resolutions than native
Custom Resolution Utility (CRU) - Page 597
Custom Resolution Utility (CRU) - Page 540
Custom Resolution Utility - Download
Custom Resolution Utility - Download
How to Downsample and Increase Refresh Rate using CRU to overclock your monitor for Gaming | Tom's Hardware Forum