What it actually takes to train your own model: the math nobody shows you
"How much GPU do you need" is the wrong question. Compute, data and knowledge don't add up — they're three gates in series, and the one almost nobody clears isn't the hardware one. With today's real pricing, a real open model's corpus, and the real logbook from a 175-billion-parameter training run, this piece does the full math — and tells you which gate you're actually standing at.