Originally released in 2012 for a whopping $1,550, the Xeon E5-2670 is attracting tons of interest among PC enthusiasts. This four-year old CPU delivers 8-cores clocked at 2.6GHz with a 3.3GHz turbo frequency and a large 20MB L3 cache. Though it was intended for use with the C600 series chipset, it's also compatible with X79 desktop motherboards, and as such supports quad-channel DDR3 memory. You're probably wondering at this point, why we are talking about an old, expensive server-grade processor? Well, late last year thousands of these processors hit the secondhand market as previous-gen servers from Facebook and others were decommissioned by used equipment recyclers. With so many processors in play and little demand for them, prices have plummeted to less than $100. Moreover, the Xeon E5-2670 supports symmetric multiprocessing, meaning you can buy two Xeon E5-2670 to create an insanely affordable 16-core/32-thread beast. That's exactly what we set out to do. Paired with a dual-socket Asrock EP2C602 motherboard and 64GB of DDR3 memory, the core components of our system came in at ~$800, which is less than you'd pay for a single octa-core i7-5960X. Read the complete review.