Update: AMD sent along a clarification of the various issues Nvidia raised regarding AMD's drivers:
"We actually moved our DirectX 9 hardware to a "legacy driver" status back in March 2009, and we were quite open about this move" [[ed: News to us]]. We've been providing updates to this driver on a quarterly basis - ironic considering the fact that we are offering more frequent updates of our "legacy" driver than some companies do of their "current" drivers. In fact we will be posting a new legacy driver in the next few days.
Also, as you probably well know, WDDM1.1 (Windows Display Driver Model) is the driver architecture required to run Windows 7. To meet Microsoft requirements, GPU's must be DirectX10 and later level hardware. As stated on our website, Windows 7 users with DirectX 9 AMD graphics hardware can use the legacy Windows Vista WDDM 1.0 drivers (as it is not possible for DirectX 9 hardware to support the WDDM 1.1 driver requirements)."
Ever-helpful Nvidia sent us an e-mail this morning with a few updates regarding Windows 7 and AMD's older 3D cards. Some of AMD's old cards are cut-off from official Windows 7 support altogether, and others are missing out on a few of Windows 7's more-advanced features. Before we accuse AMD of abandoning its customer base, we thought we'd try to track down just how many customers will be affected by this news.
The numbers for the Windows 7 cut-off issue are difficult to track down due to the age of the cards involved. As announced in a support update on its Web site, AMD plans to move its pre-DirectX 10 graphics cards to legacy status. That means AMD will no longer update the software drivers for 3D cards from its Radeon HD 1000 series or older. You can try using the most current Vista-compatible driver for those cards in Windows 7, or try to find a user-made driver, but AMD won't be able to provide you with support.
Obviously, the owners of affected cards won't be happy, but considering the most recent card on the cut-off list came out in January 2007, we humbly suggest that it's about time for those users to upgrade anyway. If that's not an option, the Vista driver might be good enough--as those cards lack support for Windows 7's more-advanced video-and-graphics processing features. As long as you can get them to work in Windows 7 at all, you shouldn't feel like you're otherwise missing out.
Affecting more recent, DirectX 10-compatible cards, Nvidia also civic-mindedly uncovered that AMD's Radeon HD 2000 and Radeon HD 3000 series apparently lack GPU compute support. GPU compute refers to a developing programming trend that off-loads processing chores for certain kinds of programs (video editing in particular) to the graphics card. This means these older AMD cards won't support Windows 7's DirectCompute standard, nor the open platform OpenCL standard.
Nvidia also culled information from the release notes accompanying AMD's newest graphics driver, Catalyst 9.1, which state that these older cards won't support Drag and Drop Transcode, one of Windows 7's more-useful GPU compute features, which automatically converts video files to the proper format when you drag them from your computer to a connected device.
Nvidia's interest in these developments come not only from wanting to promote its own 3D cards, but also from its investment in CUDA, Nvidia's own GPU computing standard. If you believe that AMD's older cards lack of this capability is significant, you obviously find GPU computing--and by association, CUDA--important. For some commercial-level users it might be, and adoption on the consumer level is growing, but it hasn't quite achieved critical feature status yet.
Raw numbers for affected customers are also hard to come by on this issue, but we can use Valve Software's Steam Hardware Survey to get an idea of the percentages. If you're unfamiliar, the Steam Hardware Survey logs system configuration information from willing participants via Valve's Steam, a popular PC game download service.
If you click on the survey's DirectX 10 GPU line, you'll see percentages for each graphics card in that category. We'll use this line as opposed to the DirectX 10 Systems category, under the assumption that plenty of XP users stayed current on graphics cards for the raw speed benefits, but held off on upgrading to Windows Vista.
Of all the survey participants who own a DirectX 10 capable graphics card, 25-percent own an AMD card. Of that 25-percent, roughly 40-percent (10.3-percent overall) own a Radeon HD 3000 or 2000 series card that lacks GPU compute capability in Windows 7. For Nvidia's part, 100-percent of its DirectX 10-capable graphics cards support the various GPU computing standards.
The irony of Nvidia's finger-pointing, of course, is that until the unspecified release of its next-generation 3D cards, 100-percent of Nvidia's customers will miss out on DirectX 11, Windows 7's 3D graphics standard. We'd predict that DirectX 11 will become a far more important feature for gamers than DirectCompute. AMD and its DirectX 11-capable Radeon HD 5800-series may represent only 0.1-percent of the Steam DirectX 10 Systems respondent base at the moment (the Steam survey has no DirectX 11-category yet), but unlike Nvidia's still-absent DirectX 11 cards, at least AMD is on the board.
Owners of older AMD cards may feel some discomfiture at being dropped from the Windows 7 list, but we only have so much sympathy for legacy technology. We're sure some of Nvidia's Windows XP-era GeForce 4000-series customers were upset to find out that Nvidia would be providing no Vista driver.
It's also fair for Nvidia to point out that AMD has not been as aggressive in pushing GPU computing. When it becomes more common--and we expect it will--AMD will certainly benefit from Nvidia bearing a larger load in putting the word out. We just have a hard time getting worked up about a few older AMD cards missing out on still-niche GPU-computing capability. Gaming is still a far more important driver of discrete 3D card purchases, and in that respect Nvidia is still a generation behind AMD.