My old workhorse, a custom built machine with an Intel Core Quad processor, 16GB of RAM, and six disk drivers (including two SSD's) bit the dust.  It may be a motherboard problem, but, whatever, it was beyond my ability to repair and Microsoft said that the motherboard manufacturer would not support Windows 10.  So I got a Dell Optiplex 7050, with a 254GB SSD and a 2TB hard drive, 16GB RAM (with two empty slots, I can double that), and an AMD RadeonT R7 450 Display Adapter.  The Intel I7-7700 processor is plenty fast.  I don't play computer games, but I think it would do well with a lot of them --- maybe except 3D (which would likely require another display adapter).. And it weighs only 12 pounds and is small, with modest room for some expansion.  My old workhorse weighed 40 pounds more (Yikes!) and was almost as tall as my desk.