SIGGRAPH 2007 is the stage where Microsoft dropped the bomb informing that the currently available DirectX 10 hardware will not support the upcoming DirectX 10.1. Microsoft has yet to confirm this piece of information through channels that are not connected with the Association for Computing Machinery's 34th annual international conference on graphics technology - SIGGRAPH 2007. However, the Redmond company did present Direct3D 10 at the event and even tackled the upcoming release, version 10.1.

Still, according to a report from DigitalBattle, Microsoft revealed that the upcoming update to be introduced to the current version of DirectX will no longer be compatible with the existing graphics cards. Microsoft made the jump from DirectX 9.x to DirectX 10 concomitantly to the transition from Windows XO to Windows Vista. The company is currently offering DirectX 10 exclusively bundled with Vista, and has faced accusations that it is forcing the migration to its latest Windows operating system in this manner.

Microsoft currently estimates that out of the 60 million licenses of Vista pushed since the customer launch of the operating system at the end of January, approximately 10 million have gone to gamers looking to take advantage of the company's freshest graphics technology. At this point in time, the Redmond company has released a pre-beta version of Windows Vista Service Pack 1 to a select group of testers.

One aspect of Vista SP1's role is to upgrade DirectX 10 to DirectX 10.1. At SIGGRAPH 2007 Microsoft did reveal that Direct3D 10.1, an integer part of DirectX 10.1 will "come soon" with Vista SP1, through the voice of Sam Glassenberg, Lead Program Manager with the Direct3D Team. Glassenberg revealed that all users have to do in order to test drive Direct3D 10.1 is to get their hands on the DirectX August SDK and Windows Vista SP1. Glassenberg additionally stated that Direct3D 10.1 and implicitly DirectX 10.1 will be "supported on upcoming hardware and in Windows Vista SP1."