DVD和HD DVD就像父子關係, 相互支援.

http://en.wikipedia.org/wiki/3X_DVD#3x_DVD
HD DVD播放時的傳輸率是故意定在DVD的3X, 就是為了利用現有的DVD來播放HD DVD的影像, 當然播放時間會縮減. 如果改用720P, 就能用較低的碼率(abr), 播放時間就會較長.

以平均碼率13mbps(abr)來計算, 一張D9可以播放大約85分鐘的1080P高清影像!
or instance, on an 8.5 GB DVD you could fit about 85 minutes of 1080p video encoded with VC-1 or AVC at an average bitrate of 13 Mbit/s,

這裡有討論用DVDR備份HD DVD, 備份後的DVDR可在HD DVD影碟機內播放高清影像.
http://forum.doom9.org/showthread.php?t=128409

燒錄方法:
BURN WITH NERO (tested with Nero 7.5.9.0)
Note: Test with PowerDVD before burning to verify audio is in sync
Note: As far as I know, only Nero works. Imgburn has not worked for me.
Note: If using DVD+R media and your burner insists on setting booktype to DVD-ROM (Pioneers), you must use another burner that allows setting booktype to the physical disk type. If using DVD-R media, it's not an issue. Once again, booktype must NOT be DVD-ROM. Yes, I know, this is the opposite of conventional wisdom.

1) Choose DVD-ROM (UDF) compilation
2) No Multisession
3) UDF tab - Enable Xbox (TM) compatibility mode
4) Add ADV_OBJ and HDDVD_TS folders to the compilation
5) If using DVD+R media, ensure book type setting is "physical disk type" in recorder options, not DVD-ROM. (burner must support this)