I tested
https://dl.fedoraproject.org/pub/alt/stage/23_Alpha_RC2/Server/i386/iso/F...
on a dual Athlon MP system and it boots fine to anaconda.
A little bit later I discovered
https://dl.fedoraproject.org/pub/alt/stage/23_Beta_RC1/Server/i386/iso/Fe...
and tested it as well, same result.
Should I have tried some other image?