Hey all, I've got a 2007 MBP Dual Core 2.2 with 4gb of RAM. I'm running PT 9 via a Digi 003, and use a pretty fair amount of plugins - Komplete, Reason, EZDrummer, Soundtoys Bundle, etc. I've got some sessions where I'm hitting a wall on my machine and running out of CPU power, and messing with the playback Engine and such isn't solving it. These sessions are glitching out and stopping playback or record, even after I've bounced some of the Instrument tracks down to audio and then made the Instrument tracks Inactive. Also getting error -6086 about losing connection with my 003 on these sessions....which could be a FW card going bad in the 003 but I'm thinking it's not, since it only appears to happen on the same sessions I have CPU issues with. Took it to Atlanta Pro Audio and they basically felt that I was just at the limit of what my machine was now capable of. So I'm thinking about upgrading to a Mac Pro. I was looking at the 8-core Nehalem with 6gb of memory, and a 2nd internal drive for audio only. I was also told that the 6-core 3.33 Westmere was faster for audio. Prices were pretty similar for those two machines....about $4000. But I found out that a friend of mine has a quad core Nehalem at 2.8ghz, with 6GB RAM and a 1TB drive that he wants to sell, it's less than a year old. So I'm thinking that I could save a good $1500 by picking that up from him, as a refurb of this model is only $2100 direct from Apple. Plus I know it's been taken care of. I'd just have to add a 2nd internal drive and be ready to go. Would I likely see a big jump in performance going from the dual core 2.2 MBP I currently have to the Quad Core 2.8? The MBP has been a horse for me for almost 5 years now. It's my first Mac so I haven't got any experience really in upgrading to a newer machine.....I would be uber pissed if I did a deal, and then didn't get any more performance out of it. So I'd appreciate you guys' opinion....thanks!