Huge system lag when loading big libraries.

Just updated from 6.5 to Cubase 7 and now whenever I load a big multichannel instance of BFD2 or any other big multichannel sample library I get huge system wide lag and freezing for at least 5-10 minutes, even after the plugins have loaded everything into ram. The poor performance lasts throughout the session and I get a lot of general lagging and stalling.

When I first tried loading BFD2 my entire system would freeze up and I’d have to reset, so I turned off ASIO-Guard and it started loading the projects, but it’s as I mentioned above. Everything worked like clockwork before the upgrade. Also this happens on both my PC and Mac systems in the same way.

My systems are:

intel i7 2600k
32gb ram
delta 1010/CI2
windows 7 x64
cubase 7 x64

mac pro
8 core xeon
12gb ram
mountain lion
cubase 7 x64

all plugins are 64 bit

In both cases I installed C7 along side 6.5, I’ve since uninstalled 6.5 and deleted/reset all prefs, but should I go ahead and do a full on reinstall of everything or could this be an issue with cubase itself?