New version 14.4 "release candidate" (i.e. still beta) drivers for AMD/ATI graphics cards are now available for both Windows and Linux, promising improvements for each platform. The Windows driver is found here and the Linux driver is here. Here are the highlights of the new Windows version:

• Support for the AMD Radeon R9 295X
• CrossFire fixes enhancements:
  • Crysis 3 – frame pacing improvements
  • Far Cry 3 – 3 and 4 GPU performance improvements at high quality settings, high resolution settings
  • Anno 2070 – Improved CrossFire scaling up to 34%
  • Titanfall – Resolved in game flickering with CrossFire enabled
  • Metro Last Light – Improved Crossfire scaling up to 10%
  • Eyefinity 3x1 (with three 4K panels) no longer cuts off portions of the application
  • Stuttering has been improved in certain applications when selecting mid-Eyefinity resolutions with V-sync Enabled
• Full support for OpenGL 4.4
  • OpenGL 4.4 supports the following extensions:
    • ARB_buffer_storage
    • ARB_enhanced_layouts
    • ARB_query_buffer_object
    • ARB_clear_texture
    • ARB_texture_mirror_clamp_to_edge
    • ARB_texture_stencil8
    • ARB_vertex_type_10f_11f_11f_rev
    • ARB_multi_bind
    • ARB_bindless_texture
    • ARB_spare_texture
    • ARB_seamless_cubemap_per_texture
    • ARB_indirect_parameters
    • ARB_compute_variable_group_size
    • ARB_shader_draw_parameters
    • ARB_shader_group_vote
• Mantle beta driver improvements:
  • BattleField 4: Performance slowdown is no longer seen when performing a task switch/Alt-tab
  • BattleField 4: Fuzzy images when playing in rotated SLS resolution with an A10 Kaveri system