HOW ELECTRICITY BECOMES INTELLIGENCE

Nothing here was ever fixed. It only moved.

One AI accelerator board and the data hall it sits in, drawn to scale. Every part of it was somebody’s answer to the constraint before it, and the reason it exists is the reason the next thing became scarce.

electricity one accelerator burns in five years
≈ $3,800
the part that burns it
≈ $30,000

Power is the cheap input. It is also the one you cannot get — because it is rationed by a queue rather than priced by a market.

2 · BOARD
OAM-CLASS ACCELERATOR BOARDplan · lid removed48 V BUS BARInference: ~120 kW rack across 48 V distribution.≈2.5 kAIVRM · 11 PHASESVRM · 11 PHASESInference: core rails on this class of part sit below 1 V.48 V → 0.8 VIInference: ~1200 W package divided by an ~0.8 V core rail.≈1.5 kA coreIPACKAGE SUBSTRATEReported: GB200-class board power per accelerator.≈1200 WRSILICON INTERPOSER100k+ MICROBUMPSH1H2H3H4H5H6H7H8Reported: HBM3E per-stack bandwidth, 8-high.1.2 TB/sRReported: eight HBM stacks per package on this class of part.×8 stacksRTENSOR / SML2HBM PHYTENSOR / SML2HBM PHYD2DCOMPUTE DIE ×2Two dies at or near the ~858 mm² reticle field. There is a second die here because the field stopped growing and the models did not.≈1600 mm² siliconIBoard power for a current-generation two-die part. Five years ago this number was under 300 W, and that is the whole reason everything below it changed.≈1200 W sustainedR30°C facility water plus roughly 0.028 K/W across the stack at 1200 W. On air the same part cannot be held below its throttle point at all — which is why this drawing has water in it.≈64°C junctionILOCAL FLUX RUNS SEVERAL TIMES THE DIE AVERAGECOLD PLATE (OVER)INOUTFACILITY WATERNICReported: per-port class rate on current AI server NICs.400 Gb/sRBOARD CONNECTOR — POWER + FABRIC TO THE TRAYAASECTION A—A · THROUGH THE PACKAGEvertical scale exaggerated · the thermal path, top to bottomCOPPER SPREADERSILICONCOOLANT · FACILITY WATERCOLD PLATETIM 2INTEGRATED HEAT SPREADERTIM 1 — THE LAST MILLIMETREHBM STACK · 8 DIES HIGHINTERPOSERSUBSTRATEBGAPCBHBMJUNCTION — HEAT IS MADE HEREALL HEAT EXITS UPWARDMODEL DEMAND↓ arrives here as workRACKDATA CENTREGRIDleaves as heat and load ↑
Hover any part of the drawing to see what it is and what opens.
Demand rises. Nothing physical has happened yet.

Why did this become a bottleneck?

Where the constraint has been

Ten stations, in the order the industry passed through them. Not one of them was a problem five years ago.

Beside the path

Not stations. A branch the constraint also runs down, the incumbent that ran out of headroom, and the material that only becomes worth costing once it has.