The JPG rendering process on 64-bit flavors of Windows Vista Service Pack 2 is inferior to that on the 32-bit variants of the operating system. As a direct consequence Microsoft explained that users would notice a degradation in operating system performance when digital images in the most common file format worldwide were rendered on x64 Vista (also including SP1), as well as x64 Windows Server 2008 RTM/SP1 and SP2. At this point in time JPG is the ubiquitous standard for digital imagery that Microsoft is attempting to kill with its own ISO standard JPEG XR (extended range), formerly known as HD Photo.

“You notice slow performance when you render a .jpg file on a computer that is running an x64-based version of Windows Server 2008 or of Windows Vista. Additionally, the performance is slower than when you render the same .jpg file on a computer that is running an x86-based version of Windows Server 2008 or of Windows Vista,” the Redmond company stated.

Microsoft is not offering an update designed to resolve the issue completely. However, users who are affected by this specific problem can turn to a hotfix made available by the software giant. But because the resolve is designed to fix 64-bit Vista SP2 and Windows Server SP2 for a select number of users, accessing the hotfix involves contacting Microsoft directly.

“This problem occurs because the image scaling process in Windows Server 2008 and in Windows Vista is not well optimized for the 64-bit processor architectures,” the company explained. “To resolve the issue, install hot fix 970987 on the affected computers that are running the x64-based versions of Windows Server 2008 or Windows Vista.”

Vista SP2 and Windows Server 2008 SP2 were released to manufacturing at the end of April 2009, and offered for download to the public starting with May 26.

Windows Server 2008 Service Pack 2 and Windows Vista Service Pack 2 - Five Language Standalone (KB948465) is available for download here.

Windows Server 2008 Service Pack 2 and Windows Vista Service Pack 2 - Five Language Standalone for x64-based systems (KB948465) is available for download here.