diff --git a/config/scripts/git-diff-blob-concurrency-benchmark.mjs b/config/scripts/git-diff-blob-concurrency-benchmark.mjs
new file mode 100644
index 00000000000..602efd00e1b
--- /dev/null
+++ b/config/scripts/git-diff-blob-concurrency-benchmark.mjs
@@ -0,0 +1,128 @@
+#!/usr/bin/env node
+// Benchmark: latency of loading one file diff, which reads two git blobs.
+//
+// The diff loaders in src/main/git/status.ts awaited their two sides in series,
+// so the second `git show` could not start until the first had fully returned.
+// The two reads are independent, so that serialization was pure added latency on
+// every diff the review panel opens.
+//
+// This spawns the real `git` binary against this repo, so it measures actual
+// process-launch and read cost rather than a model of it. Over SSH each diff is
+// one relay RPC and the two spawns run host-local inside the relay, so the same
+// relative saving applies to remote-host spawn time, not to network round trips.
+import { execFile } from 'node:child_process'
+import { performance } from 'node:perf_hooks'
+import { fileURLToPath } from 'node:url'
+
+const REPO_ROOT = fileURLToPath(new URL('../..', import.meta.url))
+const ITERATIONS = Number(process.env.ORCA_DIFF_BLOB_BENCH_ITERATIONS ?? '10')
+const WARMUP = Number(process.env.ORCA_DIFF_BLOB_BENCH_WARMUP ?? '3')
+
+for (const [name, value] of [
+  ['ORCA_DIFF_BLOB_BENCH_ITERATIONS', ITERATIONS],
+  ['ORCA_DIFF_BLOB_BENCH_WARMUP', WARMUP]
+]) {
+  if (!Number.isSafeInteger(value) || value <= 0) {
+    throw new Error(`${name} must be a positive integer, received ${value}`)
+  }
+}
+
+function git(args) {
+  return new Promise((resolve, reject) => {
+    execFile('git', args, { cwd: REPO_ROOT, maxBuffer: 256 * 1024 * 1024 }, (error, stdout) =>
+      error ? reject(error) : resolve(stdout)
+    )
+  })
+}
+
+// Pre-fix: await one side, then the other.
+async function readSequential(leftRef, rightRef, filePath) {
+  const left = await git(['show', '--end-of-options', `${leftRef}:${filePath}`])
+  const right = await git(['show', '--end-of-options', `${rightRef}:${filePath}`])
+  return left.length + right.length
+}
+
+// Post-fix: issue both, await together.
+async function readConcurrent(leftRef, rightRef, filePath) {
+  const [left, right] = await Promise.all([
+    git(['show', '--end-of-options', `${leftRef}:${filePath}`]),
+    git(['show', '--end-of-options', `${rightRef}:${filePath}`])
+  ])
+  return left.length + right.length
+}
+
+// Why interleaved: running one strategy's whole batch before the other's lets
+// cache warming, CPU-frequency drift, and background load correlate with the
+// strategy being measured. Alternating per iteration and taking medians keeps
+// that drift common to both arms.
+async function measureInterleaved(leftRef, rightRef, filePath) {
+  for (let index = 0; index < WARMUP; index += 1) {
+    await readSequential(leftRef, rightRef, filePath)
+    await readConcurrent(leftRef, rightRef, filePath)
+  }
+  const sequentialSamples = []
+  const concurrentSamples = []
+  for (let index = 0; index < ITERATIONS; index += 1) {
+    // Alternate which arm goes first so neither systematically pays a cold cache.
+    const sequentialFirst = index % 2 === 0
+    for (const runSequential of sequentialFirst ? [true, false] : [false, true]) {
+      const start = performance.now()
+      await (runSequential ? readSequential : readConcurrent)(leftRef, rightRef, filePath)
+      ;(runSequential ? sequentialSamples : concurrentSamples).push(performance.now() - start)
+    }
+  }
+  const median = (samples) => {
+    const sorted = [...samples].sort((a, b) => a - b)
+    const middle = Math.floor(sorted.length / 2)
+    return sorted.length % 2 === 0 ? (sorted[middle - 1] + sorted[middle]) / 2 : sorted[middle]
+  }
+  return { sequential: median(sequentialSamples), concurrent: median(concurrentSamples) }
+}
+
+const head = (await git(['rev-parse', 'HEAD'])).trim()
+const parent = `${head}~1`
+
+// Files that exist on both sides, spanning small to large so the fixed spawn
+// cost and the size-dependent read cost are both represented.
+const CANDIDATES = [
+  'src/main/git/status.ts',
+  'src/shared/agent-hook-listener.ts',
+  'src/renderer/src/components/TaskPage.tsx'
+]
+
+const files = []
+for (const filePath of CANDIDATES) {
+  try {
+    await git(['cat-file', '-e', `${parent}:${filePath}`])
+    await git(['cat-file', '-e', `${head}:${filePath}`])
+    files.push(filePath)
+  } catch {
+    // Skip a path that does not exist on both sides in this checkout.
+  }
+}
+if (files.length === 0) {
+  throw new Error('no benchmark file exists at both HEAD and HEAD~1 in this checkout')
+}
+
+const pad = (value, width) => String(value).padStart(width)
+console.log('One file diff = two git blob reads. Lower is better.')
+console.log(
+  `iterations=${ITERATIONS} warmup=${WARMUP} (interleaved, medians) head=${head.slice(0, 9)}`
+)
+console.log(
+  `${pad('file', 26)} ${pad('sequential', 12)} ${pad('concurrent', 12)} ${pad('speedup', 9)} ${pad('saved', 10)}`
+)
+for (const filePath of files) {
+  const sequentialBytes = await readSequential(parent, head, filePath)
+  const concurrentBytes = await readConcurrent(parent, head, filePath)
+  if (sequentialBytes !== concurrentBytes) {
+    throw new Error(`byte mismatch for ${filePath}`)
+  }
+  const { sequential, concurrent } = await measureInterleaved(parent, head, filePath)
+  console.log(
+    `${pad(filePath.split('/').pop(), 26)} ${pad(`${sequential.toFixed(1)} ms`, 12)} ${pad(`${concurrent.toFixed(1)} ms`, 12)} ${pad(`${(sequential / concurrent).toFixed(2)}x`, 9)} ${pad(`${(sequential - concurrent).toFixed(1)} ms`, 10)}`
+  )
+}
+console.log(
+  '\nThe saving is per diff opened, and is dominated by process launch rather than\nfile size — which is why it holds roughly constant across these files.'
+)
diff --git a/src/main/git/status.test.ts b/src/main/git/status.test.ts
index 2cdc41dc367..c39a4097825 100644
--- a/src/main/git/status.test.ts
+++ b/src/main/git/status.test.ts
@@ -543,11 +543,12 @@ describe('getDiff', () => {
 
     const reads = Array.from({ length: 8 }, () => getDiff('/repo', 'src/file.ts', true))
 
-    await waitForMockCalls(gitExecFileAsyncBufferMock, 1)
-    expect(gitExecFileAsyncBufferMock).toHaveBeenCalledTimes(1)
+    // Why both up front: the two sides are independent spawns issued concurrently,
+    // so 8 identical reads still collapse to exactly 2 — one per side, not per read.
+    await waitForMockCalls(gitExecFileAsyncBufferMock, 2)
+    expect(gitExecFileAsyncBufferMock).toHaveBeenCalledTimes(2)
 
     leftBlob.resolve()
-    await waitForMockCalls(gitExecFileAsyncBufferMock, 2)
     rightBlob.resolve()
 
     const results = await Promise.all(reads)
diff --git a/src/main/git/status.ts b/src/main/git/status.ts
index 34c5d750476..1375e4dca87 100644
--- a/src/main/git/status.ts
+++ b/src/main/git/status.ts
@@ -1244,21 +1244,29 @@ async function loadDiff(
   let modifiedDeleted = false
 
   try {
-    const leftBlob = staged
-      ? await readGitBlobAtOidPath(worktreePath, 'HEAD', filePath, options)
-      : compareAgainstHead
-        ? await readGitBlobAtOidPath(worktreePath, 'HEAD', filePath, options)
-        : await readUnstagedLeftBlob(worktreePath, filePath, options)
-    originalContent = leftBlob.content
-    originalIsBinary = leftBlob.isBinary
-
     if (staged) {
-      const rightBlob = await readGitBlobAtIndexPath(worktreePath, filePath, options)
+      // Why concurrent: HEAD and the index are independent `git show` spawns.
+      // Only this branch qualifies — the unstaged left read chains index→HEAD.
+      const [leftBlob, rightBlob] = await Promise.all([
+        readGitBlobAtOidPath(worktreePath, 'HEAD', filePath, options),
+        readGitBlobAtIndexPath(worktreePath, filePath, options)
+      ])
+      originalContent = leftBlob.content
+      originalIsBinary = leftBlob.isBinary
       modifiedContent = rightBlob.content
       modifiedIsBinary = rightBlob.isBinary
       modifiedDeleted = !rightBlob.exists
     } else {
-      const workingTreeBlob = await readWorkingTreeFile(path.join(worktreePath, filePath))
+      // The left chain (index→HEAD) is sequential within itself, but the working
+      // tree read is a plain fs read that does not depend on it.
+      const [leftBlob, workingTreeBlob] = await Promise.all([
+        compareAgainstHead
+          ? readGitBlobAtOidPath(worktreePath, 'HEAD', filePath, options)
+          : readUnstagedLeftBlob(worktreePath, filePath, options),
+        readWorkingTreeFile(path.join(worktreePath, filePath))
+      ])
+      originalContent = leftBlob.content
+      originalIsBinary = leftBlob.isBinary
       modifiedContent = workingTreeBlob.content
       modifiedIsBinary = workingTreeBlob.isBinary
       modifiedDeleted = !workingTreeBlob.exists
@@ -1397,8 +1405,12 @@ async function loadBranchDiff(
 ): Promise<GitDiffResult> {
   try {
     const leftPath = args.oldPath ?? args.filePath
-    const leftBlob = await readGitBlobAtOidPath(worktreePath, args.mergeBase, leftPath, options)
-    const rightBlob = await readGitBlobAtOidPath(worktreePath, args.headOid, args.filePath, options)
+    // Why concurrent: the two sides are independent `git show` spawns, so awaiting
+    // them in series doubles the latency of every diff the review panel opens.
+    const [leftBlob, rightBlob] = await Promise.all([
+      readGitBlobAtOidPath(worktreePath, args.mergeBase, leftPath, options),
+      readGitBlobAtOidPath(worktreePath, args.headOid, args.filePath, options)
+    ])
 
     return buildDiffResult(
       leftBlob.content,
@@ -1510,15 +1522,14 @@ async function loadCommitDiff(
 ): Promise<GitDiffResult> {
   try {
     const leftPath = args.oldPath ?? args.filePath
-    const leftBlob = args.parentOid
-      ? await readGitBlobAtOidPath(worktreePath, args.parentOid, leftPath, options)
-      : { content: '', isBinary: false }
-    const rightBlob = await readGitBlobAtOidPath(
-      worktreePath,
-      args.commitOid,
-      args.filePath,
-      options
-    )
+    // Why concurrent: the two sides are independent `git show` spawns. A root
+    // commit has no parent to read, so that side resolves without a spawn.
+    const [leftBlob, rightBlob] = await Promise.all([
+      args.parentOid
+        ? readGitBlobAtOidPath(worktreePath, args.parentOid, leftPath, options)
+        : Promise.resolve({ content: '', isBinary: false }),
+      readGitBlobAtOidPath(worktreePath, args.commitOid, args.filePath, options)
+    ])
 
     return buildDiffResult(
       leftBlob.content,