 However, the "Tom's Hardware" report conceded that the SPECviewperf tests "suffered heavily from the lack of support for the OpenGL graphics library under Windows Vista".For this reason the report recommended against replacing Windows XP with Vista until manufacturers made these drivers available.The report also concluded in tests involving real world applications Vista performed considerably slower, noting "We are disappointed that CPU-intensive applications such as video transcoding with XviD (DVD to XviD MPEG4) or the MainConcept H.264 Encoder performed 18% to nearly 24% slower in our standard benchmark scenarios".