I have a feeling my Mac Pro 5,1 should be faster than it is. I suspect the hard drives or how they interact with each other. Here's my setup: Mac Pro 5,1 (mid-2010) 2.8GHz quad-core OSX 10.9.5 Mavericks 24GB RAM (3x 8GB memory modules -I've learnt that this configuration should be more efficient than filling up all 4 slots) 2X (internal) SSDs: Samsung (128GB) 830-series: for OSX, apps (and admin user account) Samsung (128GB) 830-series: for Adobe Lightroom cache and Lightroom catalogs 3x (internal) hard drives: Seagate 3TB (ST3000DM001-1CH166): for all user accounts (except admin) Western Digital 3TB (WDC WD30EZRX-00MMMB0): for Time Machine backups Western Digital 3TB (WDC WD30EZRX-00MMMB0): for Chronosync backups My setup is probably not so unique except that I've separated the user account from the OSX drive (as explained here, in the Mac Performance guide). I often get he dreaded "spinning beachball", which I find a bit odd. It often happens when I try to save something and takes 4-5 seconds before it disappears (and the file-selector appears) so my guess is that a hard drive has gone to sleep and wakes up again. I suspect the slower Western Digital drives to do that (I haven't seen the need to invest in expensive high performance drives for that purpose) but the Seagate drive shouldn't have any such issues as far as I've know. Could it be that OSX needs all attached drives to spin up before doing any disk activity? Anything else I might have missed?