I'm unsure as to what I should do, whether I should sell my current computer or upgrade it. I work as a 3D designer and my primary use of my computer is rendering 3D, so my main concern is speeding up render times. My current computer is a Mac Pro 4,1 (Early 2009) 2 x 2.26 Ghz Quad-Core Intel Xeon, 16Gb RAM, ATI Radeon HD 4870 (512mb). I bought it in September 2009 and it has 9 months left of apple care. I'm prepared to spend about £1000 upgrading this computer, with my only choices being a new graphics card like the NVIDIA Quadro 4000 or upgrading the RAM which would mean buying 4GB dimms and selling the 2GB ones. Neither of which would improve render times (I believe), but will make my viewport and general usage smoother. or I could add the £1000 to the money I get for selling it, in the UK I think I could get around £2000 (I paid £3200 new), so £3000 for a new one. This could either buy a 27inch iMac 3.4ghz Quad Core i7 with AMD Radeon HD 6970M 2GB GDDR5 for about £2400 (Would this out perform my current computer at rendering, I think so) or a New 8 Core Mac Pro 2x2.4Ghz Quad Core 6gb ram ATI Radeon HD 5870 for £3033 ( I know it isn't much more powerful than the one I've already got but I presume having a newer generation of processor would be faster?). And I get an apple care refresh. I'm concerned that if I wait till the apple care runs out on my current computer it will lose resale value and if I decide to keep it, I potentially could spend money upgrading a computer that might need expensive repairs after it is out of apple care. What would you do? Any advice would be appreciated. Thanks.