# NousResearch/hermes-agent · Desktop warm session switch CPU spike fix

## Open now

- Nothing open on GitHub.

A performance issue where switching to a warm session caused the renderer main thread to run at ~100% CPU for several seconds was identified and addressed. The cluster includes the original bug report and two related fix attempts.

## TL;DR

- 3 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 1 PR(s) closed without merging.
- A fix was merged to main in PR #101931. Verify it addresses your case.
- **Recommended:** read PR #101931 (and any competing PRs below) before filing. Confirm the merged change covers your symptom.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `resolved` · deciding PR(s): `pr-101931`. This is distinct from the fix status above. Weigh it yourself.

## How this cluster was grouped

- Link evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
- Pairwise link density `1.00`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked.

## Closed / duplicate issues

- #95595: Desktop: switching to a warm session pegs renderer main thread at ~100% CPU for seconds

## Prior & competing PRs

- **#101931: fix(desktop): warm session switch no longer pegs the renderer main thread (salvage #95690)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `apps/desktop/src/app/chat/index.tsx`, `apps/desktop/src/app/chat/right-rail/preview-file.tsx`, `apps/desktop/src/app/chat/transcript-window.test.ts`, `apps/desktop/src/app/chat/transcript-window.ts`, `apps/desktop/src/app/session/hooks/use-session-actions/index.ts`, `apps/desktop/src/app/session/hooks/use-session-actions/utils.test.ts`, `apps/desktop/src/app/session/hooks/use-session-actions/utils.ts`, `apps/desktop/src/components/assistant-ui/thread/index.test.tsx`, `apps/desktop/src/components/chat/shiki-block.test.tsx`, `apps/desktop/src/components/chat/shiki-block.tsx`, `apps/desktop/src/components/chat/shiki-config.ts`, `apps/desktop/src/components/chat/shiki-highlight-cache.test.ts`, `apps/desktop/src/components/chat/shiki-highlight-cache.ts`, `apps/desktop/src/components/chat/shiki-highlighter.tsx`
- **#95690: fix(desktop): warm session switch pegs renderer main thread at ~100% CPU**. closed without merge
  - maintainer direction: category `superseded_by_pr`; implication `superseded`; refs `#101931`

## Fix status

- Merged to main in PR #101931 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-09-03`.