Slackware64-14.1
MacPro5,1
Intel Xeon Hex Core CPU W3680 @ 3.33GHz
32GB PC3-10600 DDR3
EVGA GeForce GTX 680 Mac Edition

Fresh installation as of last night via rEFInd and eLiLo on Slackware USB.
Everything seems to work fine with the exception of completely garbled console text at boot, all the way up until the login screen appears. I am using the proprietary driver from nvidia, version 352.63. This is in no way hindering me except for if I need to see boot messages and actually was present during the 1st part of booting to the USB installer, so no proprietary driver at that point.

Any ideas and/or suggestions would be much appreciated.
Thanks

Could be the kernel is too old for your hardware (although, I don't guess to know how old the hardware is). Maybe try the kernel from -current and see if that fixes your problem (don't forget to rebuild the nvidia drivers).

Or you could let your install as this and see boot messages later with dmesg, tail /var/log/messages etc

Actually, it is a mid 2012 MacPro5,1. No, the kernel is not too old, as I have been using slackware64-14.1 and the kernel from current brings no justice. I can at the very least, install slackware64-14.1 and only get the garbled screen during boot. The slackware64-current gets the garbled text for install and it does not clear at any point. My hardware is great hardware but there are apparently issues that I assume are to do with it being Mac. Actually, I believe is is something to do with my Mac Edition Nvidia card. I think I will try my Radeon card and see what happens. BBL...

Radeon works like a champ for install, fails to load upon running startx. o.O Keep in mind though that my testing is now under Slackware current. Will be reverting to 14.1 for now.