Page 1:Part 1: Laying A Theoretical Background
Page 2:Windows: Mouse As Window-Washer?
Page 3:The Limits Of 2D: One Space With Many Windows
Page 4:2.5D: The Myth Of 2D Hardware Acceleration
Page 5:Windows XP: Old School 2D And The Limits of WM_PAINT
Page 6:Windows Vista: Real Progress And The Art of Omission
Page 7:Windows 7: Return Of The Prodigal Son
Page 8:Windows 7: Radeon HD 5000-Series Cards Lack 2D Acceleration
Page 9:Tom2D Benchmark: Radeon HD 5870 Vs. GeForce GTX 285 In Windows 7
Page 10:Tom2D Benchmark Results, Continued
Page 11:Tom2D Conclusions, Preview Of Part 2
Windows 7: Return Of The Prodigal Son
The Windows 7 logo flying bravely on a field of azureTo many users, Vista earned its bad rep (or perhaps "bad rap") as a memory-hungry monster of an operating system. Nevertheless, it’s worth a second look, in light of the Windows 7 release. We must also observe that Windows 7 is more than just a cleaned up version of Vista, and finally includes many of the functions that one might expect a modern OS to deliver. Along with fundamental changes to the system itself, Windows 7 graphics give back to users what Vista took away—namely, unrestricted 2D graphics acceleration in hardware, including the GDI drawing functions.
Thanks to the introduction of WDDM 1.1, Windows 7 also prevents doubling up on memory usage (once for individual window buffers, and again for each active window in the DWM). This helps facilitate a more slimmed-down system, with more modest resource requirements. In Windows Vista, doubled-up memory consumption explains why system memory became so heavily loaded.
Running Vista, the OS grabs all the memory it can get… (Source: Microsoft)
…but Windows 7 is much more restrained (Source: Microsoft)
To supplement GDI in Windows 7, Direct2D has also been introduced. This interface uses analog-to-Direct3D conversion to exploit hardware acceleration while also supporting a more complex set of graphics functions. Direct2D enjoys the speed of GDI along with the extended capabilities of the ill-fated GDI+ interface. It still remains to be seen, however, if Direct2D can earn meaningful support from developers.
Even today, the vast majority of programs still use the GDI API for rendering and manipulation of 2D graphics elements. We’re ecstatic that Windows 7 gives back the hardware acceleration for these commands that Vista took away.
Asynchronous GDI in Windows 7 (Source: Microsoft)
Nearly ideal scaling when handing multiple windows concurrently (Source: Microsoft)Summary:
- Direct forwarding of GDI drawing commands to the graphic drivers via DWM
- Asynchronous and simultaneous processing of GDI commands for multiple windows
- Memory-conserving management strategies for the pending graphics request queue
- New and improved WDDM 1.1 drivers
Graphics Card Vendor Requirement
The return of hardware acceleration for 2D graphics also brings graphics card vendors back into the game. The drivers for Windows 7 must be specially-crafted so they can deliver hardware acceleration for native two-dimensional GDI commands, while also supporting 2.5D layering for individual windows.
This is a crucial situation for some cards. For example, the current generation of cards from ATI appears to suffer from driver-related difficulties in both of these distinct 2D graphics acceleration areas. You’ll read in the next section about how we detected and what we concluded about these issues.
- Part 1: Laying A Theoretical Background
- Windows: Mouse As Window-Washer?
- The Limits Of 2D: One Space With Many Windows
- 2.5D: The Myth Of 2D Hardware Acceleration
- Windows XP: Old School 2D And The Limits of WM_PAINT
- Windows Vista: Real Progress And The Art of Omission
- Windows 7: Return Of The Prodigal Son
- Windows 7: Radeon HD 5000-Series Cards Lack 2D Acceleration
- Tom2D Benchmark: Radeon HD 5870 Vs. GeForce GTX 285 In Windows 7
- Tom2D Benchmark Results, Continued
- Tom2D Conclusions, Preview Of Part 2