Aperture is killing my mac

I have a 56gb Aperture library and have been running this on my macbook 13" air 4gb, however it got to the point I had very little space left so I moved it over to a brand new mac mini with 8gb.

Aperture is saying its constantly importing. usually I have open, mail,postbox, Sipgate VOIP, and perhaps a browser. No real difference to what I would run on my Air. But its slow, really slow. I was worried that the mini would not cope being serial drive over the faster SSD, so I upgrade to 8GB but seriously if I open photoshop I can forget gettting any speed from it. My air performed far better and although its not what I call fast when running aperture/photoshop it was usable.

Open Photoshop and I may as well go for a coffee before I can use it and then it always feels like its loading something.

the macmini is causing me concern - is this normal, am I just expecting too much coming from SSD to serial?