I built this PC to replace my aging Mac Pro tower. It's a workstation only, and I don't game on it at all. I'm a animator / motion designer and I use After Effects and Cinema 4D for most of my production work. I use Octane for rendering 3D. I selected the components for single thread and multi thread speed, and CUDA performance.
Motherboard: I started out with a ASUS X99 Deluxe from a previous build, but I had quite a few issues with stability and the 6950x processor. I replaced it with a Deluxe II motherboard and so far it's been working fine.
Processor: The plan was to use one chip and get the most cores I could get without going to a Xeon based system. Xeon chips are great, but the slower clock speeds in single threaded apps and higher price made the 6950 the best choice for a combination of speed and core count. The CPU is overclocked to 4GHZ. I could have gone higher, but it's plenty for all of my apps, and the extra .1 or .2 ghz wasn't worth the voltage and heat.
RAM: Ram speed wasn't super critical to me so I picked up the Ripjaws RAM on sale. I will be upgrading to 128 Gigs when I find a deal on some later this year.
Video Cards: I picked up two 1080 FTW cards right before Nvidia made the recall, but since I'm not running the factory cooler, I went ahead and kept them. Most of my apps use CUDA acceleration and at the time, these were the fastest 1080 cards I could get. The Titan card just wasn't worth the money, especially when comparing rendering speeds of the 1080's and the price difference between the 1080's and the Titan.
Drives: The OCZ drive is my primary boot drive, and I have a few SSD drives for cache and other files that are leftover from the Mac. I have an external raid that I use for project files, and a WD Red internal drive as a daily backup drive.
Cooling: This was my second water cooling loop I have built, and I had quite a few components left over from a previous build. The tubing is all Primochill PETG with Revolver fittings, and Primochill clear coolant. The CPU block and GPU blocks are all EK, along with the D5 pump. The front radiator is a Hardware Labs SR2 360, and the top radiator is an EK 360 PE. Based on my previous cooling experience, I wanted to use really quiet fans and keep the rpm's to a minimum while still allowing for low temps on the components. To fit the larger radiator in the front, I had to mount the fans outside the case. I bought some modders mesh from mnpctech.com and cut out the front panel for better airflow. For cooling control, I'm using an Aquaero 6XT mounted on the drive side of the case. It's out of the way, and I didn't have a 5 1/4 mount in the Define S to mount a standard Aquaero with the display. Temps at idle are in the mid 20's on the CPU and at max load hover around 42-43C. GPU temps never get above 45C under load when rendering. Fan RPM is around 500 at idle and max load they spin up to around 800 or 900 RPM. The cards aren't in the correct slots for SLI but the second slot is still 16x. It's absolutely silent at idle and barely audible at full load.
Other accessories: I'm uisng a HUE+ for lighting control, and a NZXT IU101 for extra internal USB headers since the motherboard only had one header and I needed at least two.
Yeah, the case is kind of cluttered at the bottom, but there just wasn't room anywhere else in the case for the light controller and extension stuff. After using a full size tower in my previous build, I really wanted to try a mid tower case. Overall, even though it's a tight fit, I'm really happy with the performance and I have room for adding a TB3 card or an additional GPU if I need it.