Tachyon

The lightest real-time GPU monitor for NVIDIA cards, and the one that explains itself: what is holding your work back, when VRAM will run out, why the PC went down, and how this render compares with the last one. It only reads: it never touches clocks, fans, power limits or the network.

By Formray.

Tachyon 1.0 is the first release. The 5.0 to 5.1.1 builds were previews before 1.0; see the changelog.

Features

New in 1.3:

• Tachy v5, a redrawn Hex. A cleaner hexagon with calm, shape-driven eyes and ambient motion around him: sparkles while rendering, heat waves when hot, a sweat drop when VRAM is full, z's when sleepy. Two built-in skins, Velvet (default) and Aurora flat, switched in Settings > General > Companion skin and applied at once.
• Two new states. VRAM full (92 % or more for about 3 s, off below 85 %) and alarm (a new crash report, a GPU driver reset or the red temperature; at least 10 s, after a crash until you click Hex or the next render starts). Priority: alarm > hot > VRAM full > render > sleepy > idle.
• Preview flags. tachyon.exe --hex-demo cycles through the six states; tachyon.exe --hex-state=alarm holds one. Nothing is recorded in preview mode.

New in 1.2:

• 100 ms fast sampling. A small thread reads the clocks, power against the limit, temperature, load, the clock-limit reasons and the PCIe link ten times a second into a second fixed-size ring next to the flight recorder (15 minutes, about 352 KB). After a crash, diagnose_crash shows the last 30 s at that resolution (last_seconds): a +200 W step within 100 ms, power brake or a hardware slowdown just before the stop are named as hints. Measured on an RTX 5080: no extra CPU above the run-to-run noise (the whole Tachyon stays at 1-1.7% of one core, as 1.1.0), one extra thread.
• PCIe link history. The link against the best the GPU and slot can do. Dropping to Gen1/Gen2 at idle is normal and only counted; a narrower link (x8 in an x16 slot) or a lower generation under load is logged as degraded, with the recovery. In the status, the bottleneck evidence and the get_pcie_link tool.
• VRAM per process over time. Every 5 s, from the same per-process counters Task Manager uses (NVML has no per-process VRAM under Windows' WDDM), logged when it changes. get_process_vram answers "who held VRAM between 18:00 and 18:30?" with peak, average and a timeline per process.
• Render job markers. A render script calls tachyon mark start --job "shot 12" and tachyon mark end --job "shot 12"; Tachyon reports the job: duration, averag

... View full README on GitHub