Our School has rigs with some gen quad core i7s, and some crappy old AMD GPUs. While they are okay for basic level CAD, most of our CADers use their own rigs/laptops.
Personal RIG: That I do most of my CADing on:
CPU: Intel Core i7 5930K
MotherBoard: ROG STRIX X99 GAMING
CPU Cooler: Corsair H110i GTX AIO Water Cooler
RAM: 32 GB of Corsair Dominator Platinums
GPUs: 2x ASUS STRIX GTX 1080
1x Nvidia Titan X
PowerSupply: EVGA SuperNova 1200
Storage: 2x 500gb 850 EVO SSDs
10 gigabit connection to 12tb network NAS
CASE: Phanteks Enthoo Evolv ATX Tempered Glass
Monitors: 3x Dell P2415Q
Accessories:
Mouse: Logitech MX Master
Keyboard: Logitech G710+
Headphones: Sennheiser HD 6 MIX
3DMouse: 3Dconnexion Space Mouse Pro
Yes, I know this is way overkill, especially having 2 1080s and another titan x on top of it, but I got really lucky with sales and gifts soo ya
Total retail cost (according to pcpartpicker): about $5827.34
What I spent on it: about $2500