OK, just in case the title is unclear: Until El Cap beta (and I have the GM and I still see it, just not as often as I did before) the GT120 was enough for what I needed (I wanted the processing horsepower not gaming graphics) but now, it seems that more of the regular, everyday, rendering work is being passed on to the GPU and it is noticeably slowing down the machine even though almost no resources are being used. There is an OWC SSD, 24Gb of ram (the 32 is coming but 24 seemed plenty for a time) and the (2) 2.26 processors have been and seemingly, continue to be, plenty for most things --I am yet to encounter a calculation so large that I have to wait much; video editing, that is another story but how much of that is GPU lacking horsepower? I have looked through the forums and generally, the buying advice concerns older Mac Pros (1,1 and 3,1 mostly) rather than mine (4,1 5,1 flashed soon to have upgraded CPUs) and since these machines are most likely not running El Cap, I am not sure how relevant the points made are in as much as most of the info seems to date back to 2008. It would seem that I need a new GPU and I do not need much but I cannot have my train of thought interrupted by a beachball every time I need to switch screens while I wait for it to be drawn. When I play games, I play them on my iPhone and then, usually, only while waiting for something else. However, I type a lot and there are often more than 10 papers open at once (instances of preview). I cannot afford a 7950 but 5770 is more than doable and 5870 is a stretch but still doable. So, is the problem the GPU or something else? Would the 5770 be enough and solve the problem? I am tired of freezing while waiting for rendering (tested, music or video continues in the background unaffected but I am stuck on the particular desktop with usage below 10%) Although I feel that the GPU is to blame, I am open to ideas.