Chaps, I'm sorry this is probably a fairly obvious question, but I have spent the last few hours reading endless threads both here and elsewhere and am now no closer to a "simple" answer, and in fact a whole lot more confused! Having spent years on PC this is my first Mac and I'm struggling a little with a lot of the terminology and finding things that were easy on the PC (upgrades for example!) a complete headache. I have a mid-2010 12-core MacPro which currently has a Radeon HD5770 installed and is running 10.7.5. After much shouting and endless changing of cables and adaptors I eventually persuaded it to output to three monitors, but I now want four... In a fit of desperation I tried one of the many USB-to-video boxes which was fine in the sense that it worked, but the latency is horrendous and it's really not up to the job. So I need to do something to get four monitors up and running. It seems the "easy" way would be to add a second card, however I have no free PCIe slots - quite why the MP has only four is beyond me! In looking at AMD/ATI and Nvidia options there seem to be quite a few cards which have quad outputs but then have smallprint which says on a Mac that only two will work.... not much use then. Would something like this do? http://www.scan.co.uk/products/2gb-...pu-1006mhz-boost-1084mhz-cores-1344-dp-dl-dvi - that seems to claim four outputs? But will it melt things? The monitors are 2x Dell 24" (1920x1080), 1x Dell 30" (2560) and 1x Samsung 42" Plasma (1920x1080). I don't game on the machine, hell I don't even do email on it, it's purely for A/V work, so whilst I don't care about Cuda this or OpenGL that, I do want to to be able to handle the resolutions above simultaneously and full screen video on any one of the displays. On the other hand if the card that fits the bill happens to be a gaming card, I simply don't care - I just need the right tool for the job. The whole EFI / no boot screen thing doesn't seem to concern me - I've never seen a boot screen on this rig other than all the screens going white and it sitting there forever and a day whilst booting, so I'm not sure what I'm missing on that score - mine just sits there for an age and then up pops the desktop. So, am I chasing an impossible dream, or is there something amongst the mass of information I have read today (which is now dripping out of my ears) which would fit the bill? Thanks in advance, and I'm sorry for the tedium of the question!