The purpose behind video acceleration is to alleviate some of the strain the CPU undergoes during video playback. There are several features that improve both quality and performance in playback of MPEG-2 video streams (DVD), with support that is rivaled by S3 and beaten only by ATI's full-featured hardware DVD decoding (with iDCT).
Motion compensation is a performance feature that takes a significant load off of the CPU, bringing the system requirement down to about the level of a PII 266 (without dropping any frames). The TNT2 didn't have this, making the GeForce better in terms of DVD. It should be noted that in order to take advantage of this feature, the software decoder must support it.
DVD sub-picture alpha blending is a quality feature supported by the TNT2 and the GeForce (as well as the Rage 128, S3's Savage series and the TNT). Blending is used to smooth out the menus commonly used to modify language and sound settings in a DVD movie. Without sub-picture blending these menus would be dithered, crosshatched, and downright ugly.
Our test bed for the 3D benchmarking is as follows:
- Processors: Intel Pentium III 600MHz, Intel Pentium III 450MHz, and Celeron 300A @ 450MHz
- Memory: 128MB PC133 RAM
- Motherboard: ABIT BE-6
- Hard Drive: Western Digital 5.1 GB Ultra DMA
- Sound Card: Creative Labs SB Live! X-Gamer
- Windows 98 SE with DirectX 7
The following video cards were used with the following sets of drivers:
- Guillemot 3D Prophet DDR-DVI 32MB DDR SGRAM ver. 3.62a (120/301MHz)
- ASUS V6600 Deluxe 32MB SDR SGRAM ver. 3.62a (120/166MHz)
- ATI Rage Fury MAXX 64MB SDR SDRAM (125/143MHz)