Interesting article @ toms hardware
Intro: Aren't All Graphics Cards Equal When It Come To 2D?
Since the launch of Windows 7 a few months ago, graphics card vendors have introduced a handful of new GPUs, working to develop and roll out drivers for their products. Enough time has also passed for them to clean up the teething pains of a fresh operating system (which have been, thankfully, significantly less painful than what we saw during the move to Vista), enabling objective benchmarks on a clean slate of new technology.
We also realized that, while 3D takes center stage nowadays, there might also be some benefits for us to revisit a component of graphics that we take for granted every day without really thinking too much about it—namely, 2D. This wasn't one of those out-of-the-blue "let's add something to the test suite that hasn't been a real issue since the days when RAMDAC performance was a major differentiator" moments. More on this shortly.
Although the primary area of interest for most users is on the display speed of the Windows GUI (where Windows 7 earns lots of praise in comparison to Vista), we determined somewhat reluctantly that the supposed “graphics refresh” in Windows 7 isn’t really too fresh at all. Compared to Windows XP (and even Vista), graphics card vendors don't seem to have fully optimized for 2D graphics in Windows 7 quite yet, at least when it comes to close examination of the brand new implementation of GDI (Graphics Device Interface) API calls. What we know as 2D graphics consist of more than cool colors, object blending effects, and animated menus with drop shadows; they also require developers to get down and dirty with pixels, lines, curves, rectangles, polygons, and all kinds of other “graphics primitives,” as they’re sometimes called.
Problem 1: ATIKMDAG Stopped Responding, Then Recovered
Anybody who’s experienced this error message probably encountered it after shifting back into 2D mode after exiting a 3D application. We have to believe this very likely results from some kind of driver error.
Let’s recall: without Aero turned on, the DWM is deactivated, so there’s also no more 2D acceleration, either (this applies equally to Windows 7 as it does to Vista). Because we ran into this error repeatedly on test systems with Radeon HD 5750s and Radeon HD 5870 installed (in two different test configurations), we forcibly deactivated Aero across the board. After this evasive maneuver, these errors no longer appeared. Interestingly, the exact same situation (and remedy) also presented itself to us on a notebook PC with GeForce graphics. Whether this is just a massive coincidence or an indication of a conflict among DWM, drivers, and 2D hardware graphics acceleration, only time will tell.
Our next prime suspects include the relatively low default clock speeds for ATI cards running in 2D mode, or perhaps some issue with an early graphics BIOS. Determining whether these two possible culprits are in cahoots or working independently is something we can establish only through long-term observation, or a definite change in behavior thanks to a new driver version.
Problem 2: ATI fails to deliver 2D Hardware Acceleration for GDI, either in whole or in part
We basically stumbled onto this problem due to our difficulties in getting the Radeon HD 5870 to handle 2D graphics. Many might infer from this experience that 3D cards are made for gaming, not for 2D applications. But anybody who’s read through the preceding sections of this article must admit that this has only really become a significant point with the release of Windows 7 (and not Windows Vista). To be more specific, most 3D cards will cut the 2D mustard reasonably well these days. But a direct comparison between the GeForce GTX 285's and Radeon HD 5870's 2D capabilities results in a besting of the ATI card. In fact, even compared to Nvidia's GeForce 7050 (nForce 610i) onboard graphics solution, without its own frame buffer, the newer Radeon places second-best.
Things get even more interesting when the DWM is disabled. Even though no 2D acceleration is possible here, the ATI card jumps into the lead with regard to performance. Compared to Nvidia's GeForce board, running the ATI card with DWM disabled puts it well ahead. Even CorelDraw and AutoCAD run noticeably faster on the Radeon HD 5870 when DWM is turned off. This turns the tables on Nvidia, and contradicts our previous logic and experience benchmarking these GPUs.
Read complete 12-page articleUpdate (1/26/2010): With preliminary research into our 2D performance analysis, AMD reports back with the following:
•Tom’s Hardware has tripped over a workload area (2D lines, etc.) that we have not optimized yet.
•Until this new benchmark, we have not seen any other applications that are bottlenecked by this path, and hence have not focused on it until now.
•Our initial analysis has shown that we have no hardware limitations in this area.
•We now have our driver team engaged to optimize this path and will release a new driver to address this workload as soon as possible.
•We have already found an easy way of increasing our performance greatly, and are now going to try and schedule this in a future Catalyst (need to code in production, validate, ensure it doesn’t break anything else, etc.).
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