If you want to do it the cheap way by buying used stuff, the most expensive parts are: - $2000 for a Threadripper 3xx5WX with a socket sWRX8 mainboard - $5000

If you want to do it the cheap way by buying used stuff, the most expensive parts are: - $2000 for a Threadripper 3xx5WX with a socket sWRX8 mainboard - $5000 for 6x RTX 3090 - $350 for two 1500W PSUs - $700 for 256GB RAM You will also need PCIe extenders and perhaps some watercooling. And find a suitable case. The 2-card NVLink bridges are between $100 and $300 each (you nay want 3). All in all i think less than $10k.