General Knoppix support for those who've read the FAQ at the Wiki
HP Workstation Z640 2x Xeon E5-2623V4 32GB Ram 2x 256GB SSD Quadro 2000 Linux GA
$212.49
HP Workstation Z640 2x Xeon E5-2623V4 32GB Ram Dual 256GB SSD K420 Linux GA
$182.73
HP Z420 Workstation Xeon E5-2670 v2 2.5ghz 10-Cores 64gb 240gb SSD 1TB Win10
$199.99
HP Z440 Workstation 18Cores Xeon E5-2699 V3 128GB 1TB SSD 2TB WIFI WIN11 R5-340X
$309.99
SR1XP Intel Xeon E5-2680 v3 12 Core 30MB 2.5GHz LGA 2011-3 Grade A Processor
$4.23
Intel Xeon E5-2680 v4 SR2N7 2.40GHz 35MB 14-Core LGA2011-3 CPU Processor
$14.99
Intel Xeon E5-2697A v4 SR2K1 2.60GHz 40MB 16-Core LGA2011-3 CPU Processor
$39.99
Intel Xeon E7-8890 V4 2.20GHz 24-Core 60MB LGA2011 Server CPU Processor SR2SS
$29.99
Dell Poweredge R630 2x Xeon E5-2680 v4 2.4ghz 28-Cores / 128gb / H330 / 2x 1TB
$294.99
Dell Precision 5810 Workstation Xeon E5-1650 6C 3.5GHz 16GB 500GB Win10 K2200
$124.67