Thinking of upgrading my 3 year old mid 2011 27inch iMac base spec. The serious work I do is hobbyist use of 2D and 3D applications: adobe cloud (premier, photoshop and lightroom), Maya, Modo, Houdini, Nuke, zBrush, Mudbox, Syntheyes, Substance painter/designer. All hobby use - not professional. My iMac runs all of these (so does my MacBook Pro) but I would like to get an noticeable uplift in compute power, as I do get at times screen lag - and render times can be enormous (e.g. 8 days for a 256 frame render of a fully cgi scene I did a while ago in Modo). I had pretty much made up my mind to get a refurb base spec nMP - currently £2119. This seems like a good price - and I have enough peripherals to get me going (but would need eventually faster external storage). I like the fact that is is transportable as I travel every weekend. Then I realised that for £1999 I can get a riMac - less than the mac pro - or for £2400 - more than the mac pro - I can bump up the processor and the graphic card. I get a nice screen (probably no longer need to drive a 2nd screen), but no transportability - I would have to choose to either have the new of old iMac with me weeks/weekends. For the applications I have listed above, and bearing in mind that I wanted to see a performance improvement, but I am not making money from what I do some don't need the ultimate uplift: is the nMP a significantly higher performer with this type of app over the iMac either base or upgraded? My biggest worry though is that both have AMD cards - and that for now (but probably not forever) openCL is not as well supported as CUDA and that I am better off with a NVIDA card. Frustratingly I am worried that giving dell £880 for an XPS Desktop will get me better performance and no hardware upgrades needed as I get: 24G of RAM, and 2TB Hard drive and a 32G SSD with an NVIDIA GeForce GTX 750Ti 2GB DDR5. This route would cause me some licensing issues (as some of my licences are Mac only) so I would have to target a subset of the applications that really need the performance boost and move those over to windows. I would only ever use this machine for those few apps. This may or may not involve additional software costs - depending on what I move over. I have paid loads of money for a zBrush mac licence - but performance is not a problem - so I don't need to move it. Modo is a likely candidate but cross platform. I use Houdini apprentice but want to invest in Houdini Indie at some point - that is tied to OS so I would need to make a choice. And so on. Any useful input from Mac user of the applications I run?