GeForce series 6 and 7 chips have a processor for enhancing 2D videos, but it is not automatically enabled. Learn how to enable it at Hardwaresecrets.
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"GeForce 6 and 7 series have a dedicated 2D processor in charge of enhancing the quality of 2D videos executed by programs such as Windows Media Player. This feature was highly praised by nVidia when they released their GeForce 6 series and recently with the release of their GeForce 7 series. nVidia announces their chips from these series as “two-in-one”, since they have not only a 3D processor, but also a processor for enhancing 2D videos."