I have a 2006 Mac Pro with the following configuration: 2x 2.66ghz Dual Core NVIDIA GeForce 7300GT 10gb RAM 2x 1TB 7200 rpm HDD 2x 320 7200rpm HDD Latest build of OS X 10.5.x, Adobe CS4 Design Premium, Aperture, etc. I use it for photo editing and management primarily. Aperture is my management app, and I run a referenced library. Aperture runs slowly when processing previews and importing. Given an hour or two to "digest" a large import, however, things are reasonably quick (if not snappy). My question is: what's my bottleneck? (Graphics card, HDD speed, or something else?) I do not want a stop-gap or work-around for the snappiness issue. I sort, cull, and edit by flipping through photos at high-speed in full screen mode (20" ACD). I'm happy to run whatever tests make answering my questions easier. Thanks!