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ATXNG

Bench notes on desktop platform tuning

Tuning is a measurement problem
before it is a settings problem.

Five long notes on the parts of a desktop platform that reward instrumentation: DDR5 subtimings and the refresh window, what a regulator really delivers under a transient, the shape of a per-core voltage curve, the SPI flash the board boots from, and where the PCIe lanes actually go.

Nothing here is a settings list. Every note gives the method, the instrument, and the validation run — because the number that worked on this bench is not the number that will work on yours.

Memory & Fabric

Subtiming work on DDR5, and the lane topology the rest of the platform hangs off.

2 notes

Power & Thermals

What the regulator actually delivers under load, and how the voltage/frequency curve is shaped.

2 notes

Firmware

Reading, altering and recovering the image the board boots from.

1 note

All notes

NoteSectionReadRiskRevised
DDR5 subtiming tuning on AM5 and LGA1700 Hand-tuning DDR5 subtimings, with the refresh window as the largest single lever Memory & Fabric 16 min risk: moderate 2026-08-28
PCIe lane topology, bifurcation and link verification Splitting a x16 root port and proving on Linux that every link trained as intended Memory & Fabric 16 min risk: low 2026-08-28
VRM load line, droop and thermal analysis What the phase count buys, what LLC costs, and how to measure a rail software cannot see Power & Thermals 16 min risk: moderate 2026-08-28
Per-core Curve Optimizer: finding each core's voltage floor Per-core CO counts found by bisection, validated at idle rather than under load Power & Thermals 16 min risk: moderate 2026-08-28
UEFI firmware inspection, modification and recovery Read the SPI chip, write one region back, and recover a board that will not POST Firmware 16 min risk: can brick 2026-08-28