Minihard build-out: when does it pay for itself?
Each data hall costs money up front and earns rent once it's running. The faster halls are built, the longer new construction outruns the cash from finished ones. Move the sliders to see when funding needs peak and when the build-out starts paying for itself.
GB300 hall
Brian: $13B to build, $26.7B a year fully leased. Built from Oct 2026 until the switch to Rubin, at the pace set under Rate of build.
Vera Rubin hall
Brian: $80B full; he credits 50% rented + ⅙ via Grok = ⅔ ($53.3B). The $26B cost is Zero's placeholder, not a Brian quote.
Halls finishing before this month are GB300; from it on, Rubin. Brian: Jan 2027.
Rate of build
Halls finished per month in December of each year. Months in between follow an even slope from one December to the next; after 2029 the pace holds.
Halls are whole: the slope's running total is rounded, so 1.5 a month alternates 1 and 2. 1 → 3 gives 25 halls in 2027 (Brian's stepped base chart: 24); 1 → 3.5 gives 28 (his fully charged chart).
Cash timing, costs and starting point
Share of each type's reference revenue (Brian's selected rate). Stays fixed when prices fall.
From the build-out image: 19.2 GW at end-2027 = 1.8 GW older fleet + 3 GB300 halls at 0.4 + 24 Rubin at 0.675. GW totals also include the 1.8 GW existing fleet.
Hardware is paid in one go a month before the hall opens; the rest spreads over construction.
A prepayment arrives a month before go-live and is worked off against the first bills. It moves cash earlier; it doesn't add revenue.
Starting point · Sep 30, 2026
$89.9B cash and securities ($51.3B cash + $38.6B marketable securities)
$38.8B debt and finance leases, held flat
1.8 GW existing fleet
Q3 2026 report. Whole-company cash; Starship and Starlink also draw on it.
Colossus and other halls built before this model. Jul–Sep 2026 reported: $6.41B for the quarter (SI revenue less Cursor), $2.14B a month. $2.5B is Zero's estimate of the 1.8 GW fleet's rate. Same cost share and tax as new halls.
By year
| Year | GB300 halls | Rubin halls | GW New | GW Fleet | ARR, Dec | Revenue | Cash in | Operating cost | Tax | Construction | FCF | Borrowed | Repaid | New debt, Dec | Cash, Dec |
|---|
Reset all sliders to Brian's defaults
Dollars in billions. Cash starts at the Sep 30, 2026 balance and runs from Oct 1. Jul–Sep are shown as reported: their revenue and spending are already inside that balance and are not added again; October collects September's billings. The existing fleet earns at its own rate with the same cost share and tax. Cash on hand is spent first, then every shortfall is new debt, and surpluses repay new debt before cash builds again; no interest. New debt is the highest balance in each month, since hardware payments land mid-month. Existing debt is held flat. "Pays for itself" means every later month in the model also stays positive. Model ported from Zero's engine of 2026-10-28; replaying Brian Wang's stepped base chart through it reproduces Zero's figures exactly (tested). The default even-slope ramp builds 25 Rubin halls in 2027 instead of 24, so its numbers differ slightly.