TI's presentation say DM6467T can do 8 channel D1 H.264 encode at 30FPS. But in SPRS479c.pdf(720P H.264 Base Profile Encoder(v01.20.02) on DM6467), when encode starwars17nvdk_720x480.yuv at 30fps, average no-blocking DSP cycles is 124M, average blocking dsp cycles is 179M. So I think, 1GHz DM6467T would only can do 6 channel D1 H.264 encode.
And accroding http://processors.wiki.ti.com/index.php/Davinci_codec_performance_tables, 594MHz DM6467 can do 4 channel D1 H.264 encode, 729MHz DM6467 can do 5 channel D1 H.264 encode, can DM6467T really encode 8 channel D1 at 30fps?