Merge pull request 'feat(memory): flag RAM below rated speed (XMP/EXPO not enabled) — 0.40.0' (#44) from feat/ram-speed into main

Reviewed-on: #44

CHANGELOG.md

@@ -5,6 +5,26 @@ All notable changes to RigDoctor are recorded here. Format follows
 (`MAJOR.MINOR.PATCH`, pre-1.0). `__version__` and `pyproject.toml` must match the git
 release tag (so the auto-updater, D18, can compare versions).
 
+## [0.40.0] - 2026-05-22
+### Added
+- **RAM speed / XMP-EXPO check.** Inventory now shows each module's configured speed and, when it's
+  below the rated speed, the rating (e.g. `4800 MT/s (rated 5600)`); **System Health** flags it
+  ("RAM at 4800 MT/s (rated 5600 MT/s)") with the fix — enable XMP/EXPO in BIOS. With the profile
+  off, dmidecode only reports the JEDEC base, so the rated speed is read from both dmidecode and
+  the part number (matched against known DDR5 speed grades, so no false positives). Needs dmidecode
+  (root / launch elevation). Completes the "underperforming hardware" trio with PCIe gen + refresh.
+
+## [0.39.0] - 2026-05-22
+### Added
+- **Displays in the Inventory.** A new `core/displays.py` lists each connected monitor with its
+  resolution and current/max refresh — e.g. `DP-1 · Samsung LC34G55T → 3440x1440 @ 165 Hz`. Reads
+  GNOME's Mutter `DisplayConfig` over D-Bus (works on X11 *and* Wayland), falling back to `xrandr`
+  on other X11 desktops.
+- **System Health flags monitors below their max refresh.** If a monitor supports a higher refresh
+  at its current resolution (e.g. a 165 Hz panel set to 60 Hz — an easily-missed gaming setting),
+  Health reports it with the fix (raise it in Display settings). Max is computed at the *current*
+  resolution, so it never suggests dropping resolution.
+
 ## [0.38.0] - 2026-05-22
 ### Added
 - **PCIe link in the Inventory.** Each NVMe drive now shows its negotiated PCIe link next to the
@@ -12,6 +32,11 @@ release tag (so the auto-updater, D18, can compare versions).
   (`current/max_link_speed` + width). If a drive negotiates below its capability (a slower M.2
   slot, lane-sharing, or a downtrain) it's flagged: `PCIe Gen3 x4 (capable of Gen4 x4)`. So you
   can confirm a Gen4 SSD is actually in a Gen4 slot. (SATA disks show no PCIe link.)
+- **System Health flags downtrained NVMe links.** A new check warns when an NVMe drive negotiates
+  fewer PCIe lanes than it supports (almost always motherboard **lane-sharing** — a GPU/second
+  card or another M.2 stealing lanes) and notes speed-only reductions as info (a slower slot or
+  idle ASPM). The GPU is deliberately excluded — NVIDIA drops its PCIe gen/width at idle, so a
+  snapshot would false-alarm.
 
 ## [0.37.1] - 2026-05-22
 ### Fixed

README.md

@@ -51,30 +51,20 @@ apt pulls the GUI dependencies (PySide6, pyte) automatically:
 sudo apt install ./rigdoctor_*_all.deb        # CLI only: add --no-install-recommends
 ```
 
-**Or add the apt repository** for `apt install` + automatic updates. The registry is public and
-GPG-signed — no token needed; just add the signing key and a deb822 source:
+**Or add the apt repository** for `apt install` + automatic updates (the registry is public and
+GPG-signed — no token needed):
 
 ```bash
-# signing key → dearmored into the keyring
-sudo install -d -m 0755 /etc/apt/keyrings
-curl -fsSL https://git.jesseyvanofferen.com/api/packages/jessey/debian/repository.key \
-  | sudo gpg --dearmor -o /etc/apt/keyrings/gitea-jessey.gpg
-
-# the source (modern deb822 format, GPG-verified, all-arch)
-sudo tee /etc/apt/sources.list.d/rigdoctor.sources >/dev/null <<'EOF'
-Types: deb
-URIs: https://git.jesseyvanofferen.com/api/packages/jessey/debian
-Suites: stable
-Components: main
-Architectures: all
-Signed-By: /etc/apt/keyrings/gitea-jessey.gpg
-EOF
-
-sudo apt update && sudo apt install rigdoctor
+sudo curl https://git.jesseyvanofferen.com/api/packages/jessey/debian/repository.key -o /etc/apt/keyrings/gitea-jessey.asc
+echo "deb [arch=all signed-by=/etc/apt/keyrings/gitea-jessey.asc] https://git.jesseyvanofferen.com/api/packages/jessey/debian stable main" | sudo tee /etc/apt/sources.list.d/gitea.list
+sudo apt update
+sudo apt install rigdoctor
 ```
 
 Then `sudo apt upgrade` keeps it current.
 
+Then `sudo apt upgrade` keeps it current.
+
 ### Any distro — self-extracting `.run` (no root)
 
 Download **`rigdoctor-<version>-installer.run`** from the releases page and run it. It installs

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "rigdoctor"
-version = "0.38.0"
+version = "0.40.0"
 description = "Modular hardware monitoring & crash diagnostics for Linux gamers."
 readme = "README.md"
 requires-python = ">=3.11"

src/rigdoctor/__init__.py

@@ -1,3 +1,3 @@
 """RigDoctor — modular hardware monitoring & crash diagnostics for Linux gamers."""
 
-__version__ = "0.38.0"
+__version__ = "0.40.0"

src/rigdoctor/core/displays.py

@@ -0,0 +1,148 @@
+"""Connected displays (M5): resolution + current/max refresh per monitor.
+
+GNOME exposes the authoritative data over D-Bus (Mutter `DisplayConfig.GetCurrentState`),
+which works on both X11 and Wayland — read via `busctl --json`. Plain X11 desktops fall back
+to `xrandr`. Other Wayland compositors (sway/KDE) aren't covered yet and degrade to empty.
+Stdlib only; every probe fails soft. Max refresh is computed at the *current* resolution, so
+"can go faster" never suggests dropping resolution.
+"""
+
+from __future__ import annotations
+
+import json
+import re
+import shutil
+import subprocess
+from dataclasses import dataclass
+
+# A few common PNP monitor-vendor IDs → friendly names (best-effort; unknown codes pass through).
+_PNP = {
+    "SAM": "Samsung", "DEL": "Dell", "GSM": "LG", "LGD": "LG", "AUS": "ASUS", "ACR": "Acer",
+    "BNQ": "BenQ", "MSI": "MSI", "AOC": "AOC", "VSC": "ViewSonic", "HWP": "HP", "HPN": "HP",
+    "PHL": "Philips", "GBT": "Gigabyte", "APP": "Apple", "DGC": "Dell",
+}
+
+
+@dataclass
+class Monitor:
+    connector: str          # e.g. "DP-1"
+    name: str               # e.g. "Samsung LC34G55T" ("" if unknown, e.g. xrandr)
+    width: int
+    height: int
+    refresh: float          # current Hz
+    max_refresh: float      # max Hz available at the current resolution
+
+    @property
+    def can_go_faster(self) -> bool:
+        """True if a meaningfully higher refresh is available at the current resolution."""
+        return self.max_refresh - self.refresh > 1.0
+
+    def label(self) -> str:
+        return f"{self.connector} · {self.name}".rstrip(" ·") if self.name else self.connector
+
+
+def _run(cmd: list[str], timeout: float = 8.0) -> str:
+    try:
+        proc = subprocess.run(cmd, capture_output=True, text=True, timeout=timeout)
+        if proc.returncode == 0:
+            return proc.stdout
+    except (subprocess.SubprocessError, OSError):
+        pass
+    return ""
+
+
+def _parse_mutter(out: str) -> list[Monitor]:
+    """Parse `busctl --json` output of Mutter DisplayConfig.GetCurrentState.
+
+    data = [serial, monitors, logical_monitors, props]; each monitor is
+    [[connector, vendor, product, serial], [modes], props]; each mode is
+    [id, width, height, refresh, scale, [scales], {props}] where props may hold is-current.
+    """
+    try:
+        data = json.loads(out)["data"]
+        raw_monitors = data[1]
+    except (json.JSONDecodeError, KeyError, IndexError, TypeError):
+        return []
+    monitors: list[Monitor] = []
+    for mon in raw_monitors:
+        try:
+            connector, vendor, product = mon[0][0], mon[0][1], mon[0][2]
+            modes = mon[1]
+        except (IndexError, TypeError):
+            continue
+        current = None
+        for m in modes:
+            props = m[6] if len(m) > 6 and isinstance(m[6], dict) else {}
+            if (props.get("is-current") or {}).get("data"):
+                current = m
+                break
+        if current is None:
+            continue
+        w, h, r = int(current[1]), int(current[2]), float(current[3])
+        max_r = max((float(m[3]) for m in modes if int(m[1]) == w and int(m[2]) == h), default=r)
+        name = f"{_PNP.get(vendor, vendor)} {product}".strip()
+        monitors.append(Monitor(connector, name, w, h, r, max_r))
+    return monitors
+
+
+def _parse_xrandr(out: str) -> list[Monitor]:
+    """Parse `xrandr --query`: an output line with the active WxH+x+y, then indented mode lines
+    whose rates carry `*` for the current one."""
+    monitors: list[Monitor] = []
+    out_re = re.compile(r"^(\S+) connected.*?(\d+)x(\d+)\+\d+\+\d+")
+    mode_re = re.compile(r"^\s+(\d+)x(\d+)\s+(.+)$")
+    name = ""
+    cw = ch = 0
+    cur_r = max_r = 0.0
+
+    def flush() -> None:
+        if name and cw and cur_r:
+            monitors.append(Monitor(name, "", cw, ch, cur_r, max_r or cur_r))
+
+    for line in out.splitlines():
+        mo = out_re.match(line)
+        if mo:
+            flush()
+            name, cw, ch = mo.group(1), int(mo.group(2)), int(mo.group(3))
+            cur_r = max_r = 0.0
+            continue
+        mm = mode_re.match(line)
+        if mm and name and int(mm.group(1)) == cw and int(mm.group(2)) == ch:
+            for tok in mm.group(3).split():
+                try:
+                    rate = float(tok.rstrip("*+"))
+                except ValueError:
+                    continue
+                max_r = max(max_r, rate)
+                if "*" in tok:
+                    cur_r = rate
+    flush()
+    return monitors
+
+
+def _mutter() -> list[Monitor]:
+    exe = shutil.which("busctl")
+    if not exe:
+        return []
+    out = _run([exe, "--user", "--json=short", "call", "org.gnome.Mutter.DisplayConfig",
+                "/org/gnome/Mutter/DisplayConfig", "org.gnome.Mutter.DisplayConfig",
+                "GetCurrentState"])
+    return _parse_mutter(out) if out.strip() else []
+
+
+def _xrandr() -> list[Monitor]:
+    if not shutil.which("xrandr"):
+        return []
+    return _parse_xrandr(_run(["xrandr", "--query"]))
+
+
+def collect() -> list[Monitor]:
+    """Connected monitors, via the first backend that returns any (Mutter, then xrandr)."""
+    for backend in (_mutter, _xrandr):
+        try:
+            monitors = backend()
+        except Exception:
+            monitors = []
+        if monitors:
+            return monitors
+    return []

src/rigdoctor/core/health.py

@@ -251,6 +251,78 @@ def check_live_temps() -> list[Finding]:
     )]
 
 
+def check_pcie_links() -> list[Finding]:
+    """Flag NVMe drives linked below their PCIe capability — a slower slot or, most often,
+    motherboard lane-sharing where a GPU/second card or another M.2 steals lanes from the slot.
+
+    Width reductions are reliable (reported as warnings); speed-only reductions are info (they can
+    also be normal link power management at idle). The GPU is intentionally not checked here:
+    NVIDIA drops its PCIe gen *and* width at idle, so a point-in-time snapshot is misleading.
+    """
+    from . import inventory
+
+    findings: list[Finding] = []
+    for name, dev in inventory.nvme_controllers():
+        cur_g, cur_w, max_g, max_w = inventory.read_link(dev)
+        if not cur_g or not max_g:
+            continue
+        if max_w and cur_w and cur_w != max_w:  # fewer lanes → almost always lane-sharing
+            findings.append(Finding(
+                WARNING, "PCIe", f"{name} linked at x{cur_w} (supports x{max_w})",
+                f"{name} negotiated PCIe Gen{cur_g} x{cur_w}, but the drive supports "
+                f"Gen{max_g} x{max_w}. Fewer lanes is usually motherboard lane-sharing — a GPU or a "
+                "second card in a PCIe slot, or another populated M.2, can steal lanes from this slot.",
+                "Check your board manual's lane-sharing table; move the drive to a full-x4 "
+                "(often CPU-attached) M.2 slot."))
+        elif cur_g < max_g:  # full width but a lower generation → slower slot or idle ASPM
+            findings.append(Finding(
+                INFO, "PCIe", f"{name} linked at Gen{cur_g} (supports Gen{max_g})",
+                f"{name} negotiated PCIe Gen{cur_g} but supports Gen{max_g}. This can be a slower "
+                "(chipset or older) M.2 slot, or normal link power management (ASPM) at idle.",
+                "If you expect full speed, check the slot and the BIOS PCIe/ASPM settings."))
+    return findings
+
+
+def check_displays() -> list[Finding]:
+    """Flag monitors running below their max refresh rate at the current resolution — e.g. a
+    165 Hz panel set to 60 Hz, a common and easily-missed gaming setting (read-only suggestion)."""
+    from . import displays
+
+    findings: list[Finding] = []
+    for m in displays.collect():
+        if m.can_go_faster:
+            findings.append(Finding(
+                INFO, "Display",
+                f"{m.connector} at {round(m.refresh)} Hz (supports {round(m.max_refresh)} Hz)",
+                f"{m.name or m.connector} is running at {round(m.refresh)} Hz at "
+                f"{m.width}x{m.height}, but supports {round(m.max_refresh)} Hz at that resolution.",
+                "Raise the refresh rate in your desktop's Display settings (GNOME: Settings → Displays)."))
+    return findings
+
+
+def check_memory_speed() -> list[Finding]:
+    """Flag RAM running below its rated speed — i.e. the XMP (Intel) / EXPO (AMD) profile isn't
+    enabled, leaving memory bandwidth on the table. Needs dmidecode (root); silent without it."""
+    from . import elevation, inventory
+
+    priv = elevation.privileged()
+    dmi = priv["dmidecode"] if (priv and priv.get("dmidecode")) else inventory._dmidecode()
+    worst: tuple[int, int] | None = None  # (configured, rated) with the biggest gap
+    for m in dmi.get("memory", []):
+        configured, rated = inventory.module_speed(m)
+        if configured and rated and configured < rated:
+            if worst is None or (rated - configured) > (worst[1] - worst[0]):
+                worst = (configured, rated)
+    if worst is None:
+        return []
+    configured, rated = worst
+    return [Finding(
+        INFO, "Memory", f"RAM at {configured} MT/s (rated {rated} MT/s)",
+        f"Memory is running at {configured} MT/s but the modules are rated {rated} MT/s — the "
+        "XMP/EXPO profile isn't enabled, so you're leaving memory bandwidth on the table.",
+        "Enable XMP (Intel) or EXPO (AMD) in your BIOS/UEFI to run at the rated speed.")]
+
+
 def run_health_checks(include_journal: bool = True) -> list[Finding]:
     """Run all checks and return findings sorted by severity (worst first).
 
@@ -273,5 +345,8 @@ def run_health_checks(include_journal: bool = True) -> list[Finding]:
     else:
         findings += check_smart()
     findings += check_live_temps()
+    findings += check_pcie_links()
+    findings += check_displays()
+    findings += check_memory_speed()  # uses elevation data if present, else dmidecode (root)
     findings.sort(key=lambda f: _ORDER.get(f.severity, 9))
     return findings

src/rigdoctor/core/inventory.py

@@ -86,6 +86,35 @@ def _firmware(dmi: dict) -> Section:
     return Section("Firmware", items)
 
 
+# Common DDR5 XMP/EXPO speed grades (MT/s) — used to read a kit's rated speed from its part
+# number, since with XMP/EXPO off dmidecode only reports the JEDEC base (e.g. 4800).
+_DDR_SPEEDS = {4800, 5200, 5600, 6000, 6200, 6400, 6600, 6800, 7000, 7200, 7600, 8000, 8200, 8400}
+
+
+def _mts(value: str) -> int | None:
+    """Parse a dmidecode speed like '4800 MT/s' (or 'MHz') to its integer MT/s."""
+    m = re.match(r"\s*(\d+)", value or "")
+    return int(m.group(1)) if m else None
+
+
+def _rated_from_part(part: str) -> int | None:
+    """The highest known DDR speed-grade appearing as a 4-digit token in a part number."""
+    grades = [int(n) for n in re.findall(r"(?<!\d)(\d{4})(?!\d)", part or "") if int(n) in _DDR_SPEEDS]
+    return max(grades) if grades else None
+
+
+def module_speed(m: dict) -> tuple[int | None, int | None]:
+    """(configured, rated) MT/s for a dmidecode Memory Device.
+
+    Configured = what it's actually running at; rated = the highest of dmidecode's reported max
+    and the part-number speed-grade (so an unapplied XMP/EXPO profile is still detected).
+    """
+    configured = _mts(m.get("Configured Memory Speed") or m.get("Configured Clock Speed") or m.get("Speed", ""))
+    candidates = [s for s in (_mts(m.get("Speed", "")), _rated_from_part(m.get("Part Number", ""))) if s]
+    rated = max(candidates) if candidates else None
+    return configured, rated
+
+
 def _memory(dmi: dict) -> Section:
     items: list[tuple[str, str]] = []
     try:
@@ -99,8 +128,12 @@ def _memory(dmi: dict) -> Section:
     if modules:
         items.append(("Modules", str(len(modules))))
         for i, m in enumerate(modules):
-            desc = " · ".join(p for p in (m.get("Size"), m.get("Type"), m.get("Speed"), m.get("Part Number")) if p)
-            items.append((f"Slot {i}", desc))
+            configured, rated = module_speed(m)
+            speed = f"{configured} MT/s" if configured else m.get("Speed", "")
+            if rated and configured and rated > configured:  # XMP/EXPO not applied
+                speed += f" (rated {rated})"
+            parts = (m.get("Size"), m.get("Type"), speed, m.get("Part Number"))
+            items.append((f"Slot {i}", " · ".join(p for p in parts if p)))
     elif shutil.which("dmidecode"):
         items.append(("Modules", "run with admin for module details"))
     return Section("Memory", items)
@@ -134,11 +167,10 @@ def _gen(speed: str) -> int | None:
     return _PCIE_GEN.get(tok)
 
 
-def _link_desc(dev: Path) -> str:
-    """Describe a PCI device's negotiated PCIe link, noting if it's below its max.
+def read_link(dev: Path) -> tuple[int | None, str, int | None, str]:
+    """Negotiated/max PCIe link for a PCI device dir: (cur_gen, cur_width, max_gen, max_width).
 
-    e.g. 'PCIe Gen4 x4', or 'PCIe Gen3 x4 (capable of Gen4 x4)' when downtrained / in a
-    slower slot.
+    Widths are the raw sysfs strings (e.g. '4'); gens are ints (4) or None when unreadable.
     """
     def rd(name: str) -> str:
         try:
@@ -146,8 +178,17 @@ def _link_desc(dev: Path) -> str:
         except OSError:
             return ""
 
-    cur_g, cur_w = _gen(rd("current_link_speed")), rd("current_link_width")
-    max_g, max_w = _gen(rd("max_link_speed")), rd("max_link_width")
+    return (_gen(rd("current_link_speed")), rd("current_link_width"),
+            _gen(rd("max_link_speed")), rd("max_link_width"))
+
+
+def _link_desc(dev: Path) -> str:
+    """Describe a PCI device's negotiated PCIe link, noting if it's below its max.
+
+    e.g. 'PCIe Gen4 x4', or 'PCIe Gen3 x4 (capable of Gen4 x4)' when downtrained / in a
+    slower slot.
+    """
+    cur_g, cur_w, max_g, max_w = read_link(dev)
     if not cur_g or not cur_w:
         return ""
     desc = f"PCIe Gen{cur_g} x{cur_w}"
@@ -156,6 +197,16 @@ def _link_desc(dev: Path) -> str:
     return desc
 
 
+def nvme_controllers() -> list[tuple[str, Path]]:
+    """Each NVMe controller as (name, pci-device-dir), e.g. ('nvme0', /sys/.../device)."""
+    base = Path("/sys/class/nvme")
+    try:
+        entries = [p for p in base.iterdir() if re.fullmatch(r"nvme\d+", p.name)]
+    except OSError:
+        return []
+    return sorted((p.name, p / "device") for p in entries)
+
+
 def _nvme_link(block_name: str) -> str:
     """PCIe link for an NVMe block device (nvme0n1 → controller nvme0); '' for non-NVMe."""
     m = re.match(r"(nvme\d+)", block_name)
@@ -183,10 +234,18 @@ def _storage() -> Section:
 
 
 def _display() -> Section:
-    return Section("Display", [
+    from . import displays
+
+    items = [
         ("Session", os.environ.get("XDG_SESSION_TYPE", "unknown")),
         ("Desktop", os.environ.get("XDG_CURRENT_DESKTOP") or os.environ.get("DESKTOP_SESSION", "unknown")),
-    ])
+    ]
+    for m in displays.collect():
+        val = f"{m.width}x{m.height} @ {round(m.refresh)} Hz"
+        if m.can_go_faster:
+            val += f" (supports {round(m.max_refresh)} Hz)"
+        items.append((m.label(), val))
+    return Section("Display", items)
 
 
 def _dmidecode() -> dict:

tests/test_displays.py

@@ -0,0 +1,67 @@
+"""Tests for display detection (Mutter D-Bus JSON + xrandr parsers)."""
+
+import unittest
+
+from rigdoctor.core import displays
+
+# Minimal Mutter GetCurrentState (busctl --json) shape: current mode is 60 Hz, panel max 165 Hz.
+_MUTTER_60 = (
+    '{"type":"x","data":[1,[[["DP-1","SAM","LC34G55T","S"],['
+    '["3440x1440@60",3440,1440,60.0,1.0,[1.0],{"is-current":{"type":"b","data":true}}],'
+    '["3440x1440@165",3440,1440,165.0,1.0,[1.0],{"is-preferred":{"type":"b","data":true}}]'
+    '],{}]],[],{}]}'
+)
+_MUTTER_MAX = (
+    '{"type":"x","data":[1,[[["DP-1","SAM","LC34G55T","S"],['
+    '["3440x1440@165",3440,1440,165.0,1.0,[1.0],{"is-current":{"type":"b","data":true}}],'
+    '["3440x1440@60",3440,1440,60.0,1.0,[1.0],{}]'
+    '],{}]],[],{}]}'
+)
+
+_XRANDR_60 = """Screen 0: minimum 8 x 8, current 3440 x 1440, maximum 16384 x 16384
+DP-1 connected primary 3440x1440+0+0 (normal left inverted right x axis y axis) 800mm x 335mm
+   3440x1440     60.00*+  165.00   100.00
+   2560x1440    165.00    60.00
+HDMI-1 disconnected (normal left inverted right x axis y axis)
+"""
+
+
+class MutterParseTests(unittest.TestCase):
+    def test_parses_and_flags_higher_refresh(self):
+        mons = displays._parse_mutter(_MUTTER_60)
+        self.assertEqual(len(mons), 1)
+        m = mons[0]
+        self.assertEqual(m.connector, "DP-1")
+        self.assertEqual(m.name, "Samsung LC34G55T")  # PNP code SAM mapped
+        self.assertEqual((m.width, m.height), (3440, 1440))
+        self.assertEqual(round(m.refresh), 60)
+        self.assertEqual(round(m.max_refresh), 165)
+        self.assertTrue(m.can_go_faster)
+
+    def test_at_max_is_not_flagged(self):
+        m = displays._parse_mutter(_MUTTER_MAX)[0]
+        self.assertEqual(round(m.refresh), 165)
+        self.assertFalse(m.can_go_faster)
+
+    def test_garbage_returns_empty(self):
+        self.assertEqual(displays._parse_mutter("not json"), [])
+        self.assertEqual(displays._parse_mutter("{}"), [])
+
+
+class XrandrParseTests(unittest.TestCase):
+    def test_current_and_max_refresh(self):
+        mons = displays._parse_xrandr(_XRANDR_60)
+        self.assertEqual(len(mons), 1)  # disconnected output ignored
+        m = mons[0]
+        self.assertEqual(m.connector, "DP-1")
+        self.assertEqual((m.width, m.height), (3440, 1440))
+        self.assertEqual(round(m.refresh), 60)
+        self.assertEqual(round(m.max_refresh), 165)
+        self.assertTrue(m.can_go_faster)
+
+    def test_empty_returns_empty(self):
+        self.assertEqual(displays._parse_xrandr(""), [])
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_health.py

@@ -1,8 +1,20 @@
 """Tests for the M4 health report's log scanner (synthetic input)."""
 
 import unittest
+from pathlib import Path
+from unittest import mock
 
-from rigdoctor.core.health import CRITICAL, WARNING, run_health_checks, scan_journal_text
+from rigdoctor.core import displays, health
+from rigdoctor.core.health import (
+    CRITICAL,
+    INFO,
+    WARNING,
+    check_displays,
+    check_memory_speed,
+    check_pcie_links,
+    run_health_checks,
+    scan_journal_text,
+)
 
 
 class HealthScanTests(unittest.TestCase):
@@ -42,5 +54,70 @@ class HealthScanTests(unittest.TestCase):
         self.assertEqual(ranks, sorted(ranks))
 
 
+class PcieLinkCheckTests(unittest.TestCase):
+    def _with_link(self, cur_g, cur_w, max_g, max_w):
+        # one fake NVMe controller returning the given link tuple
+        return (mock.patch("rigdoctor.core.inventory.nvme_controllers",
+                           return_value=[("nvme0", Path("/x"))]),
+                mock.patch("rigdoctor.core.inventory.read_link",
+                           return_value=(cur_g, cur_w, max_g, max_w)))
+
+    def test_reduced_width_is_a_warning_about_lane_sharing(self):
+        ctrls, link = self._with_link(4, "2", 4, "4")  # Gen4 x2 but supports x4
+        with ctrls, link:
+            findings = check_pcie_links()
+        self.assertEqual(len(findings), 1)
+        self.assertEqual(findings[0].severity, WARNING)
+        self.assertIn("lane-sharing", findings[0].detail)
+
+    def test_reduced_speed_only_is_info(self):
+        ctrls, link = self._with_link(3, "4", 4, "4")  # Gen3 x4 but supports Gen4
+        with ctrls, link:
+            findings = check_pcie_links()
+        self.assertEqual(len(findings), 1)
+        self.assertEqual(findings[0].severity, INFO)
+
+    def test_full_speed_no_finding(self):
+        ctrls, link = self._with_link(4, "4", 4, "4")
+        with ctrls, link:
+            self.assertEqual(check_pcie_links(), [])
+
+
+class DisplayCheckTests(unittest.TestCase):
+    def test_lower_than_max_refresh_is_flagged(self):
+        mon = displays.Monitor("DP-1", "Samsung LC34G55T", 3440, 1440, 60.0, 165.0)
+        with mock.patch("rigdoctor.core.displays.collect", return_value=[mon]):
+            findings = check_displays()
+        self.assertEqual(len(findings), 1)
+        self.assertEqual(findings[0].severity, INFO)
+        self.assertIn("165", findings[0].title)
+
+    def test_at_max_refresh_no_finding(self):
+        mon = displays.Monitor("DP-1", "Samsung LC34G55T", 3440, 1440, 165.0, 165.0)
+        with mock.patch("rigdoctor.core.displays.collect", return_value=[mon]):
+            self.assertEqual(check_displays(), [])
+
+
+class MemorySpeedCheckTests(unittest.TestCase):
+    def _dmi(self, configured, part):
+        return {"memory": [{"Configured Memory Speed": configured, "Speed": configured,
+                            "Part Number": part}]}
+
+    def test_flags_unapplied_expo(self):
+        dmi = self._dmi("4800 MT/s", "CMK32GX5M2B5600Z36")
+        with mock.patch("rigdoctor.core.elevation.privileged", return_value=None), \
+             mock.patch("rigdoctor.core.inventory._dmidecode", return_value=dmi):
+            findings = check_memory_speed()
+        self.assertEqual(len(findings), 1)
+        self.assertEqual(findings[0].severity, INFO)
+        self.assertIn("5600", findings[0].title)
+
+    def test_no_flag_at_rated(self):
+        dmi = self._dmi("5600 MT/s", "CMK32GX5M2B5600Z36")
+        with mock.patch("rigdoctor.core.elevation.privileged", return_value=None), \
+             mock.patch("rigdoctor.core.inventory._dmidecode", return_value=dmi):
+            self.assertEqual(check_memory_speed(), [])
+
+
 if __name__ == "__main__":
     unittest.main()

tests/test_inventory.py

@@ -54,5 +54,23 @@ class PcieLinkTests(unittest.TestCase):
         self.assertEqual(inventory._nvme_link("sda"), "")
 
 
+class MemorySpeedTests(unittest.TestCase):
+    def test_rated_speed_from_part_number(self):
+        self.assertEqual(inventory._rated_from_part("CMK32GX5M2B5600Z36"), 5600)
+        self.assertEqual(inventory._rated_from_part("F5-6000J3038F16G"), 6000)
+        self.assertIsNone(inventory._rated_from_part("NoSpeedHere"))
+
+    def test_detects_unapplied_expo(self):
+        # XMP/EXPO off: dmidecode only sees JEDEC 4800; the 5600 is in the part number.
+        m = {"Configured Memory Speed": "4800 MT/s", "Speed": "4800 MT/s",
+             "Part Number": "CMK32GX5M2B5600Z36"}
+        self.assertEqual(inventory.module_speed(m), (4800, 5600))
+
+    def test_at_rated_speed(self):
+        m = {"Configured Memory Speed": "5600 MT/s", "Speed": "5600 MT/s",
+             "Part Number": "CMK32GX5M2B5600Z36"}
+        self.assertEqual(inventory.module_speed(m), (5600, 5600))
+
+
 if __name__ == "__main__":
     unittest.main()