I would bow down to a 1337HaXoR vanity. just 6years for 50% 
How slow is your computer?
@ 20 MKey / sec (GeForce 660 Ti), it's more like 20 days for 50%
Someone with better hardware then me could probably do it in a week.
http://imgur.com/NVejAgv
Non case sensitive would take a couple days for me. If you have like 4 top of the line GPUs you could do it in half a day.
Sold the last of my rigs a week ago