General Knoppix support for those who've read the FAQ at the Wiki
Dell Poweredge R630 2x Xeon E5-2680 v3 2.5ghz 24-Cores / 32gb / 500gb / 495w
$164.99
Dell Precision 7910 Xeon E5-2623 v3 3.0GHz 32GB RAM 512GB SSD Nvidia GTX 980
$489.00
Intel Xeon E5-2698 V4 2.20GHz 50MB 20 Core 9.6GT/s 135W CPU Processor SR2JW
$61.99
Lot of 2 Intel Xeon E5-2697 V4 2.3GHz 18 Core LGA 2011-3 Server CPU Processor
$80.55
Intel Xeon W-2155 LGA2066 10-Core Processor 3.30GHz SR3LR
$139.99
Intel Xeon E5-2699 V3 2.3GHz LGA Server Processor CPU
$27.99
Intel Xeon 18-Core E5-2699v3 @ 2.3GHz 45MB 145W Processor SR1XD CPU
$29.95
Intel Xeon E3-1270 V2 SR0P6 Quad-Core 3.5 GHz CPU Processor 69W LGA1155
$18.90
Intel Xeon Gold 6254 3.10GHz SRF92 18-Core Processor Socket LGA3647
$239.95
Supermicro MotherBoard X11SPi-TF Xeon Single CPU Socket LGA3647 w/Heatsink
$279.99