"Xenoppix-x86_64(Xen3.0.2+KNOPPIX-x86_64-5.0.1) CD size" is released. It exploits latest CPU (Intel Core2 Duo and AMD Athlon64).
http://unit.aist.go.jp/itri/knoppix/xen/index-en.html

Xenoppix-x86_64 boots both X86 and X86_64 linux kernel on HVM of Xen.
Xenoppix-x86_64 looks like KNOPPIX but all packages are replaced for X86_64.
Xenoppix-x86_64 also works as KNOPPIX-x86_64.
Boot loader is GRUB which supports EFI. It enables boot on Intel MAC.
Linux kernel is 2.6.16 for Domain0 of Xen and 2.6.17 for KNOPIX-x86_64.

# Performance of KNOPPIX-x86_64
We compared Pi calculation on KNOPPIX-x86_64 and KNOPPIX32. The software
calculates 3 Million digits of Pi.
Download http://h2np.net/pi/pi_quick_start.tar.gz

Code:
-----------------------------------------------
CPU              KNOPPIX-x86_64   KNOPPIX5.0.1
                (Linux 2.6.17)   (Linux2.6.17)
-----------------------------------------------
AMD Opteron 152         4.96     8.38
AMD Athlon64x2 4000+    6.59    11.24
AMD Turion64x2 TL-50    8.28    13.95
(Acer Aspire 5100)
Intel Core2 Duo 6400    8.38    12.31
Intel Core2 DuoT7200   10.58    13.31
(Intel MAC)
-----------------------------------------------
# Download
ISO file: knoppix-x86_64-v5.0.1CD-20061006-xen3.0.2.iso (MD5: 58de7fbb0deda2645228dfd8dacc0414)
Bittorrent file: http://unit.aist.go.jp/itri/knoppix/....2.iso.torrent
HTTP: http://ring.riken.jp/archives/linux/...6-xen3.0.2.iso
FTP: ftp://ring.riken.jp/archives/linux/k...6-xen3.0.2.iso