Root input
A variable the model cannot yet compute from anything else. It may be a genuine edge of the scenario, or physics that nobody has broken down yet.
gpu_stack/readme/frontdoor.txt
A virtual AI datacenter you can question. It estimates what a training run costs in time, power, and money, states how sure it is, and shows you what every number is built from.
read_graph.exe
Start with a human question, then follow the named dependencies upstream. Every hop should tell you whether you are looking at an equation, a scenario value, or an unresolved root input.
token_journey.exe
Each station is one layer of the model. The lamp lights as the token passes through, and the trip always ends at an invoice.
Symbolic causal backbone
The registry keeps every equation next to its units, sources, constraints, scenario assumptions, and the boundaries it has not resolved. The research layer adds the things that can contradict it: real observations, timed events, interventions, uncertainty, residuals, held-out splits, and regret. A held-out split is data the model never saw while it was being fitted, so a prediction on that data is a real test. Regret is what the choice cost you compared with the choice you would have made knowing the outcome. A complete graph is not the same thing as a tested one.
Constant.Variable: clocks, voltages, tariffs, GPU counts, batch sizes, and facility assumptions.One answer at the top rests on every layer beneath it. Click a layer to see what it owes.
layers.sys
The visible machine is a building, but the model treats it as a constraint bundle: grid interconnect, substations, cooling loops, water, occupancy, capex, operations, and uptime.
trace_target.exe
Cost per token is not a lone price. It depends on run cost, token count, facility power, throughput, utilization, hardware choices, and root assumptions that still need better evidence.
Every hop keeps its label, and that is what makes the graph useful. If a hop cannot be worked out from equations or scenario assignments, it comes back as a named missing boundary instead of a guess.
cone_browser.exe
Pick a target, then click any node to open its direct dependencies. Each hop shows its unit, its scope, meaning the part of the system it belongs to, and whether it is an equation, a root input, or a physics constant. Root inputs carry a gold badge because they are the debt you can still see.
root_debt.dat
root-debt ranks unresolved root inputs by how much depends on them. A large family is not automatically a bad one. The ranking exists so you know which unknowns are expensive right now.
physical.lithography.medium with total weight 3014.The bars scale the five README weights against the heaviest family. Nothing new is being measured here.
CLI.exe
This is a research instrument, not a polished app, and right now that is the useful thing to be. Ask it what exists, what is still unresolved, and where a claim bottoms out.
python -m gpu_stack.cli stats
python -m gpu_stack.cli verify --profile fast
python -m gpu_stack.cli resolve econ.cost.per_token --preset scenarios.dense_training_cost_fixture --trace --missing
python -m gpu_stack.cli root-debt --families --limit 5
python -m gpu_stack.cli scenario-report scenarios.dense_training_cost_fixture --json
python -m gpu_stack.cli next-work
python -m gpu_stack.cli experiment-protocol E001 --json
python -m gpu_stack.cli experiment-run E001 --scenario experiments/e001-beyond-one-datacenter/screening-scenario-v1.json --output result.json --observatory-output docs/data/e001-screening-v1.json
A variable the model cannot yet compute from anything else. It may be a genuine edge of the scenario, or physics that nobody has broken down yet.
Everything upstream of one number: the variables, equations, assumptions, and constants you need in order to explain it.
A named set of fixed input values, so a target resolves the same way every time. Synthetic fixtures are test anchors, not claims about real prices.
Model FLOPs Utilization: the share of the machine's peak math rate that training actually uses. When it is low, the run is usually waiting on memory instead of doing math, which is exactly what a roofline chart is drawn to show.
High Bandwidth Memory: the fast memory stacked right next to the accelerator. Moving data in and out of it is often the real speed limit, not the math.
Power Usage Effectiveness: total facility power divided by IT equipment power. Cooling and everything else the building draws shows up here.
Tracing a result back to mechanics and evidence. Replaying compute, communication, checkpoint, outage, and recovery events one at a time. Keeping observations, assumptions, priors, modeled values, and unmeasured claims clearly apart.
E001 now has explicit recovery mechanics and three measured learning stages. LC3 held useful work equal across policies: adaptive continuation kept the learning and saved both attempted work and opportunity ticks, the scheduled time it no longer needed, but it went past its frozen device-energy bound. None of that shows a frontier-scale multi-site run converges, and energy measured at one GPU is not energy measured at a facility.
next_work.exe