This is my first computer build. It is a workstation I pieced together in about three hours that met three criteria: inexpensive, reliable, quiet, and FAST!
I got the regular i7-4790 instead of the overclocking-enabled i7-4790K to meet those four goals, in addition to getting a smallish, but ample for my needs, 256GB SSD instead of a hard drive with 8X the capacity. Even skipped out on getting a CD/DVD drive as my laptop has one for the once a year I need to play a CD/DVD. Figured I could add that later if need be.
You can see how speedy the computer is in this video. A friend of mine calls it "The Beast"!
I also used IC Diamond thermal paste, so add a few more dollars to the specs below.
I purchased Windows 8.1 Pro from an authorized Microsoft refurbisher. All prices below include tax and shipping.
When I do more CAD work, I may increase the RAM to 16 GB, but for now, everything I throw at it is virtually instantaneous, just as the video shows. The computer is virtually inaudible too. Very happy with this build.