# 0hmx - @shibo i can see it running on blacksmit...

Channel: #contributor
Source: https://discord.com/channels/1233487248129921135/1526948038566871130
Started: 2026-07-15T13:46:22.074000+00:00
Last activity: 2026-07-15T13:51:05.631000+00:00

## 0hmx — 2026-07-15T13:46:21.717000+00:00

<@778624824875941908> i can see it running on blacksmith-32vcpu-ubuntu-2404-arm

## shibo — 2026-07-15T13:47:15.497000+00:00

according to codex
The decisive A/B is PR #1642:
Both runs checked out the exact same commit, 79b36e0.
Both used Bun 1.3.14, @tscircuit/checks@0.0.144, identical top-level dependency versions, 32 vCPUs, and 32 benchmark workers.
The fast job reports Host CPU Manufacturer: Ampere.
The slow job reports Host CPU Manufacturer: ARM.
P50 increased 47%, P95 increased 45%, and benchmark wall time increased roughly 46%, while completion, DRC rate, and via count stayed identical.

## 0hmx — 2026-07-15T13:49:35.992000+00:00

i gess <@757706909351411845> because i do not see any workflow edit only the var can be changed

## shibo — 2026-07-15T13:49:37.604000+00:00

maybe ~~github~~ blacksmith changed their runner, I assumed it was your pr

## 0hmx — 2026-07-15T13:50:25.953000+00:00

i think this is on blacksmith

  - Workflow runner configuration did not change: both jobs requested blacksmith-32vcpu-ubuntu-2404-arm.
  - Physical runner instance did change: Blacksmith allocated two different ephemeral machines.
  - GitHub reports the same runner label and runner group for both jobs, but different runner IDs.
  - The host metadata changed from Ampere to ARM, strongly explaining the ~46% slowdown.

## 0hmx — 2026-07-15T13:51:05.631000+00:00

giving different machine than requested