diff --git a/proto-cuda/nvrtc/packfile.h b/proto-cuda/nvrtc/packfile.h
index ba1719e8e..4f2315f23 100644
--- a/proto-cuda/nvrtc/packfile.h
+++ b/proto-cuda/nvrtc/packfile.h
@@ -283,13 +283,17 @@ static int pf_load(const char* dir, PfPack* pk, char* err, size_t cap) {
         strcpy(ehex, e2); strcpy(dhex, d2);
     }
     if (!ehex[0] || !dhex[0]) return pf_fail(err, cap, "no seeds: neither seeds.txt nor IGNEUM_SEED_BYTES_HEX / IGNEUM_DAY_BYTES_HEX in program.h (a pack from igneum-pow export --seed <name> has no byte seeds)");
-    if (strlen(ehex) != 64) return pf_fail(err, cap, "epoch seed is not 64 hex characters");
+    // The chain's epoch seed is 32 bytes (64 hex characters). A pack exported from a seed STRING (igneum-pow export
+    // --seed <name>, the read-width experiment's packs of 5 October 2026) carries the string's bytes instead; the
+    // seed-word re-derivation below checks either form, so any even-length hex seed is accepted here. The serve
+    // protocol still carries 64-hex seeds; a string-seed pack can only be benched (--bench, --bench-pack, --check).
+    if (strlen(ehex) < 2 || strlen(ehex) % 2 != 0) return pf_fail(err, cap, "epoch seed is not an even-length hex string");
     strcpy(pk->epochHex, ehex); strcpy(pk->dayHex, dhex);
     // The seed words derived from the bytes must be the pack's own words: otherwise the pack and the seeds disagree
     {
         uint32_t w[8];
-        if (!pf_unhex(ehex, bytes, 32, &blen) || blen != 32) return pf_fail(err, cap, "epoch seed hex is malformed");
-        pf_seed_words_from_bytes(bytes, 32, w);
+        if (!pf_unhex(ehex, bytes, sizeof(bytes), &blen) || blen == 0) return pf_fail(err, cap, "epoch seed hex is malformed");
+        pf_seed_words_from_bytes(bytes, blen, w);
         if (memcmp(w, pk->seedw, 32) != 0) return pf_fail(err, cap, "the epoch seed bytes do not give the pack's IGNEUM_SEEDW_INIT (wrong seeds.txt for this pack?)");
         if (!pf_unhex(dhex, bytes, sizeof(bytes), &blen)) return pf_fail(err, cap, "day seed hex is malformed");
         pf_seed_words_from_bytes(bytes, blen, w);
diff --git a/relay/playbooks/readwidth-5090-bench.ps1 b/relay/playbooks/readwidth-5090-bench.ps1
new file mode 100644
index 000000000..2a2e5190e
--- /dev/null
+++ b/relay/playbooks/readwidth-5090-bench.ps1
@@ -0,0 +1,66 @@
+# Igneum run job (second round, bench only; the first round's packs were refused for a string seed): the read-width experiment on PC 2's RTX 5090 (machine 1ccfe586), 5 October 2026 (docs/plans/read-width.md).
+# Published as a plain `run` job (NOT --stop-miners): the installed app keeps every other card mining; this script switches
+# off ONLY the NVIDIA card in the app through POST <app.url>api/cards, waits for its worker to stop, runs the fetched
+# igneum-worker-cuda.exe (--memprobe, then --bench on every pack of the fetched packs folder), and switches the card back
+# on with the settings it had. Every result line starts with RESULT so `node tools/jobs.mjs <job id>` shows them.
+$ErrorActionPreference = 'Continue'
+function Say([string] $m) { Write-Host ("[" + (Get-Date -Format 'HH:mm:ss') + "] " + $m) }
+$jobs = Split-Path $env:IGNEUM_JOB_DIR
+$fetched = Join-Path $jobs 'fetch-readwidth-20261005c'
+$exe = Join-Path $fetched 'igneum-worker-cuda.exe'
+$packs = Join-Path $fetched 'packs-readwidth'
+if (-not (Test-Path $exe)) { Write-Output "RESULT error worker missing at $exe (the fetch job runs first)"; exit 2 }
+if (-not (Test-Path $packs)) { Write-Output "RESULT error packs missing at $packs"; exit 2 }
+$inst = @("$env:LOCALAPPDATA\Programs\Igneum Miner", "$env:ProgramFiles\Igneum Miner") | Where-Object { Test-Path (Join-Path $_ 'igneum-worker-cuda.exe') } | Select-Object -First 1
+if (-not $inst) { Write-Output 'RESULT error no installed igneum-worker-cuda.exe (the NVRTC DLLs come from there)'; exit 2 }
+Get-ChildItem $inst -Filter 'nvrtc*.dll' | Copy-Item -Destination $fetched -Force
+Write-Output "RESULT worker $exe sha256 $((Get-FileHash -Algorithm SHA256 $exe).Hash.ToLower()) with $((Get-ChildItem $fetched -Filter 'nvrtc*.dll').Count) NVRTC DLL(s) from $inst"
+
+# the app: switch off the NVIDIA card only, remember its settings
+$appDir = $env:IGNEUM_APP_DIR
+if (-not $appDir) { $appDir = Join-Path $env:LOCALAPPDATA 'igneum\app' }
+$urlFile = Join-Path $appDir 'app.url'
+$url = $null
+if (Test-Path $urlFile) { $url = (Get-Content -LiteralPath $urlFile -Raw).Trim() }
+$card = $null
+if ($url) {
+  try {
+    $st = Invoke-RestMethod -Uri ($url + 'api/state') -Method GET -TimeoutSec 10
+    $card = $st.mining.cards | Where-Object { $_.vendor -eq 'nvidia' } | Select-Object -First 1
+    if (-not $card) { $card = $st.cards | Where-Object { $_.vendor -eq 'nvidia' } | Select-Object -First 1 }
+  } catch { Say ("api/state: " + $_.Exception.Message) }
+}
+if ($card) {
+  Write-Output ("RESULT card " + $card.key + " enabled=" + $card.enabled + " identities=" + $card.identities + " power_pct=" + $card.power_pct + " state=" + $card.state)
+  $body = @{ cards = @(@{ key = $card.key; enabled = $false; identities = [int]$card.identities; power_pct = [int]$card.power_pct }) } | ConvertTo-Json -Depth 5
+  try { Invoke-RestMethod -Uri ($url + 'api/cards') -Method POST -Body $body -ContentType 'application/json' -TimeoutSec 10 | Out-Null; Say "card off requested" } catch { Say ("api/cards off: " + $_.Exception.Message) }
+  $t = 0
+  while ($t -lt 90) {
+    Start-Sleep -Seconds 5; $t += 5
+    try { $st = Invoke-RestMethod -Uri ($url + 'api/state') -Method GET -TimeoutSec 10; $c2 = $st.mining.cards | Where-Object { $_.key -eq $card.key }; if (-not $c2) { $c2 = $st.cards | Where-Object { $_.key -eq $card.key } }; if ($c2 -and $c2.state -eq 'off' -and $c2.pid -eq 0) { break } } catch { }
+  }
+  Write-Output ("RESULT card-off after " + $t + " s")
+  Start-Sleep -Seconds 5
+} else { Write-Output 'RESULT card none-found (the app is not running or has no NVIDIA card); measuring with whatever else runs on the GPU' }
+
+& nvidia-smi --query-gpu=name,driver_version,power.limit,clocks.sm,clocks.mem,memory.used,temperature.gpu --format=csv,noheader 2>&1 | ForEach-Object { "RESULT gpu-before $_" }
+# the probe ran in run-readwidth-5090-20261005 (bench-log, 5 October 2026); this second run is the bench only
+foreach ($pk in @('w4', 'w16', 'w64', 'w64x4', 'mixA-0', 'mixA-1', 'mixA-2', 'mixA-3', 'mixA-4', 'mixA-5', 'mixB-0', 'mixB-1', 'mixB-2', 'mixB-3', 'mixB-4', 'mixB-5')) {
+  $d = Join-Path $packs $pk
+  Write-Output "RESULT bench $pk start $(Get-Date -Format HH:mm:ss)"
+  & $exe --bench --pack $d --batches 5 --batch-log2 24 --block-warps 1 2>&1 | ForEach-Object { "RESULT $_" }
+  & $exe --bench --pack $d --batches 5 --batch-log2 24 --block-warps 8 2>&1 | Where-Object { $_ -match '^RESULT|error|FAIL' } | ForEach-Object { "RESULT $_" }
+}
+foreach ($pk in @('scr0k32', 'scr2k32', 'scr4k32', 'scr8k32', 'scr2k128', 'scr4k128', 'scr8k128')) {
+  $d = Join-Path $packs $pk
+  Write-Output "RESULT bench $pk start $(Get-Date -Format HH:mm:ss)"
+  & $exe --bench --pack $d --batches 5 --batch-log2 24 --block-warps 1 2>&1 | ForEach-Object { "RESULT $_" }
+  & $exe --bench --pack $d --batches 5 --batch-log2 24 --block-warps 1 --warps 4096 2>&1 | Where-Object { $_ -match '^RESULT|error|FAIL|variant 5' } | ForEach-Object { "RESULT $_" }
+}
+& nvidia-smi --query-gpu=power.draw,clocks.sm,clocks.mem,memory.used,temperature.gpu --format=csv,noheader 2>&1 | ForEach-Object { "RESULT gpu-after $_" }
+
+if ($card) {
+  $body = @{ cards = @(@{ key = $card.key; enabled = [bool]$card.enabled; identities = [int]$card.identities; power_pct = [int]$card.power_pct }) } | ConvertTo-Json -Depth 5
+  try { Invoke-RestMethod -Uri ($url + 'api/cards') -Method POST -Body $body -ContentType 'application/json' -TimeoutSec 10 | Out-Null; Write-Output ("RESULT card restored enabled=" + $card.enabled) } catch { Write-Output ("RESULT error card restore: " + $_.Exception.Message) }
+}
+exit 0
diff --git a/relay/playbooks/readwidth-9070-bench.ps1 b/relay/playbooks/readwidth-9070-bench.ps1
new file mode 100644
index 000000000..7ce46fe37
--- /dev/null
+++ b/relay/playbooks/readwidth-9070-bench.ps1
@@ -0,0 +1,68 @@
+# Igneum run job (second round, bench only; the first round's packs were refused for a string seed): the read-width experiment on PC 1's RX 9070 XT on the eGPU (machine ae432dc7), 5 October 2026 (docs/plans/read-width.md).
+# Published as a plain `run` job (NOT --stop-miners): the installed app keeps every other card mining; this script switches
+# off ONLY the NVIDIA card in the app through POST <app.url>api/cards, waits for its worker to stop, runs the fetched
+# igneum-worker-opencl.exe (--memprobe, then --bench on every pack of the fetched packs folder), and switches the card back
+# on with the settings it had. Every result line starts with RESULT so `node tools/jobs.mjs <job id>` shows them.
+$ErrorActionPreference = 'Continue'
+function Say([string] $m) { Write-Host ("[" + (Get-Date -Format 'HH:mm:ss') + "] " + $m) }
+$jobs = Split-Path $env:IGNEUM_JOB_DIR
+$fetched = Join-Path $jobs 'fetch-readwidth-20261005c'
+$exe = Join-Path $fetched 'igneum-worker-opencl.exe'
+$packs = Join-Path $fetched 'packs-readwidth'
+if (-not (Test-Path $exe)) { Write-Output "RESULT error worker missing at $exe (the fetch job runs first)"; exit 2 }
+if (-not (Test-Path $packs)) { Write-Output "RESULT error packs missing at $packs"; exit 2 }
+Write-Output "RESULT worker $exe sha256 $((Get-FileHash -Algorithm SHA256 $exe).Hash.ToLower())"
+# the card's OpenCL device index on the current (3683.0) platform, from the worker's own list (the older platform's duplicate is marked dup)
+$list = & $exe --list 2>&1
+$list | ForEach-Object { "RESULT list $_" }
+$dev = $null
+foreach ($l in $list) { if ($l -match '^\s*\[(\d+)\].*gfx1201' -and $l -notmatch 'dup') { $dev = [int]$Matches[1]; break } }
+if ($null -eq $dev) { Write-Output 'RESULT error no gfx1201 device in --list'; exit 2 }
+Write-Output "RESULT device $dev"
+
+# the app: switch off the NVIDIA card only, remember its settings
+$appDir = $env:IGNEUM_APP_DIR
+if (-not $appDir) { $appDir = Join-Path $env:LOCALAPPDATA 'igneum\app' }
+$urlFile = Join-Path $appDir 'app.url'
+$url = $null
+if (Test-Path $urlFile) { $url = (Get-Content -LiteralPath $urlFile -Raw).Trim() }
+$card = $null
+if ($url) {
+  try {
+    $st = Invoke-RestMethod -Uri ($url + 'api/state') -Method GET -TimeoutSec 10
+    $card = $st.mining.cards | Where-Object { ($_.vendor -eq 'amd' -and $_.key -match 'gfx1201') } | Select-Object -First 1
+    if (-not $card) { $card = $st.cards | Where-Object { ($_.vendor -eq 'amd' -and $_.key -match 'gfx1201') } | Select-Object -First 1 }
+  } catch { Say ("api/state: " + $_.Exception.Message) }
+}
+if ($card) {
+  Write-Output ("RESULT card " + $card.key + " enabled=" + $card.enabled + " identities=" + $card.identities + " power_pct=" + $card.power_pct + " state=" + $card.state)
+  $body = @{ cards = @(@{ key = $card.key; enabled = $false; identities = [int]$card.identities; power_pct = [int]$card.power_pct }) } | ConvertTo-Json -Depth 5
+  try { Invoke-RestMethod -Uri ($url + 'api/cards') -Method POST -Body $body -ContentType 'application/json' -TimeoutSec 10 | Out-Null; Say "card off requested" } catch { Say ("api/cards off: " + $_.Exception.Message) }
+  $t = 0
+  while ($t -lt 90) {
+    Start-Sleep -Seconds 5; $t += 5
+    try { $st = Invoke-RestMethod -Uri ($url + 'api/state') -Method GET -TimeoutSec 10; $c2 = $st.mining.cards | Where-Object { $_.key -eq $card.key }; if (-not $c2) { $c2 = $st.cards | Where-Object { $_.key -eq $card.key } }; if ($c2 -and $c2.state -eq 'off' -and $c2.pid -eq 0) { break } } catch { }
+  }
+  Write-Output ("RESULT card-off after " + $t + " s")
+  Start-Sleep -Seconds 5
+} else { Write-Output 'RESULT card none-found (the app is not running or has no NVIDIA card); measuring with whatever else runs on the GPU' }
+
+# the probe ran in run-readwidth-9070-20261005 (bench-log, 5 October 2026); this second run is the bench only
+foreach ($pk in @('w4', 'w16', 'w64', 'w64x4', 'mixA-0', 'mixA-1', 'mixA-2', 'mixA-3', 'mixA-4', 'mixA-5', 'mixB-0', 'mixB-1', 'mixB-2', 'mixB-3', 'mixB-4', 'mixB-5')) {
+  $d = Join-Path $packs $pk
+  Write-Output "RESULT bench $pk start $(Get-Date -Format HH:mm:ss)"
+  & $exe --bench-pack --pack $d --batches 5 --batch-log2 24 --device $dev 2>&1 | ForEach-Object { "RESULT $_" }
+  & $exe --bench-pack --pack $d --batches 5 --batch-log2 24 --device $dev --group-warps 8 2>&1 | Where-Object { $_ -match '^RESULT|error|FAIL' } | ForEach-Object { "RESULT $_" }
+}
+foreach ($pk in @('scr0k32', 'scr2k32', 'scr4k32', 'scr8k32', 'scr2k128', 'scr4k128', 'scr8k128')) {
+  $d = Join-Path $packs $pk
+  Write-Output "RESULT bench $pk start $(Get-Date -Format HH:mm:ss)"
+  & $exe --bench-pack --pack $d --batches 5 --batch-log2 24 --device $dev 2>&1 | ForEach-Object { "RESULT $_" }
+  & $exe --bench-pack --pack $d --batches 5 --batch-log2 24 --device $dev --warps 4096 2>&1 | Where-Object { $_ -match '^RESULT|error|FAIL|variant 5' } | ForEach-Object { "RESULT $_" }
+}
+
+if ($card) {
+  $body = @{ cards = @(@{ key = $card.key; enabled = [bool]$card.enabled; identities = [int]$card.identities; power_pct = [int]$card.power_pct }) } | ConvertTo-Json -Depth 5
+  try { Invoke-RestMethod -Uri ($url + 'api/cards') -Method POST -Body $body -ContentType 'application/json' -TimeoutSec 10 | Out-Null; Write-Output ("RESULT card restored enabled=" + $card.enabled) } catch { Write-Output ("RESULT error card restore: " + $_.Exception.Message) }
+}
+exit 0