I don't have a graphics processor in my computer. It's just a Windows 7 ,i5 processor, 8 GB RAM, off-the-shelf Computer, and I haven't noticed any change in performance. It just works.
What exactly do you mean by slow? What are you trying to do which is slower then LR5?
Did you turn off «Face Detection»?
Daniel (from Switzerland)
It probably depends on your hardware.
On my Win7 box with a really old ATI video card and 8 gig of RAM, LR6 seems about the same speed, maybe marginally faster, with the GPU not supported.
Turning off the GPU support may or may not change things for you.
On my Macs, it is much faster... particularly once it has upgraded all the data from my previous library.
Double check your preferences for the application. Particularly the Catalog Setting for Standard Previews (under File Handling tab).