V17 slowness

 Hi,
I have been using V15 since release, and have just downloaded the V17 in trial mode. The first thing I did was to import an xref, and straight away noticed the lag and unresposiveness. I thought it maybe just the file, so I did the same exercise in V15, and was so much quicker both panning/scrolling/orbiting etc. There is a definite lag in V17 that I am not seeing in V15.

Anybody else notice it, or is there anything that can be done to speed it up?

Thanks

Richard