Stress testing works on any x86-64 CPU, including Intel: per-core cycling, MCE
detection, topology detection, temperature monitoring, and every stress backend work
without the ryzen_smu module. Only the Curve Optimizer features (SMU read/write) are
AMD-specific.
| Generation | Example CPUs | CO Range | SMU Mailbox | PBO Limits | Boost Limit | Notes |
|---|---|---|---|---|---|---|
| Zen 1 / Zen+ | 1800X, 2700X | -- | RSMU | PPT/TDC/EDC | Read only | No CO -- PBO limits and scalar only (Matisse SMU fallback) |
| Zen 2 (Matisse) | 3600X, 3700X, 3900X, 3950X | -- | RSMU | PPT/TDC/EDC | Read only | No CO -- PBO limits and scalar only |
| Zen 2 (Castle Peak) | 3960X, 3970X, 3990X | -- | RSMU | PPT/TDC/EDC | Read only | Threadripper, no CO |
| Zen 3 (Vermeer) | 5600X, 5800X, 5900X, 5950X | -30 to +30 | MP1 | PPT/TDC/EDC | Read only | Full CO support |
| Zen 3 (Cezanne) | 5600G, 5700G | -30 to +30 | MP1 | PPT/TDC/EDC | -- | APU, same CO commands as Vermeer |
| Zen 3 (Rembrandt) | 6800U, 6900HX | -30 to +30 | MP1 | PPT/TDC/EDC | -- | APU, uses Cezanne CO commands |
| Zen 3D (Warhol) | 5800X3D | -30 to +30 | MP1 | PPT/TDC/EDC | Read only | V-Cache; be conservative (>-25 risky) |
| Zen 4 (Raphael) | 7600X, 7700X, 7900X, 7950X | -50 to +30 | RSMU | PPT/TDC/EDC | Read/Write | Extended negative range |
| Zen 4 X3D (Raphael) | 7800X3D, 7900X3D, 7950X3D | -50 to +30 | RSMU | PPT/TDC/EDC | Read/Write | V-Cache; same commands as Raphael |
| Zen 4 (Phoenix) | 7840U, 7840HS, 8845HS | -50 to +30 | RSMU | PPT/TDC/EDC | -- | APU (Phoenix / Hawk Point) |
| Zen 4 (Dragon Range) | 7945HX, 7845HX | -50 to +30 | RSMU | PPT/TDC/EDC | Read/Write | Mobile, same silicon as Raphael |
| Zen 4 (Storm Peak) | 7980X, 7970X TR | -50 to +30 | RSMU | PPT/TDC/EDC | Read/Write | Threadripper PRO |
| Zen 5 (Granite Ridge) | 9600X, 9700X, 9900X, 9950X | -60 to +10 | RSMU | PPT/TDC/EDC | Read/Write | Widest negative CO range |
| Zen 5 X3D (Granite Ridge) | 9800X3D, 9900X3D, 9950X3D | -60 to +10 | RSMU | PPT/TDC/EDC | Read/Write | V-Cache; same commands as Granite Ridge |
| Zen 5 (Strix Point) | Ryzen AI 9 HX 370 | -60 to +10 | RSMU | PPT/TDC/EDC | -- | APU |
| Zen 5 (Strix Halo) | Ryzen AI Max | -60 to +10 | RSMU | PPT/TDC/EDC | -- | APU, uses Strix Point commands |
| Zen 5 (Shimada Peak) | Zen 5 Threadripper | -60 to +10 | RSMU | PPT/TDC/EDC | Read/Write | Different SMU addresses (get_co=0xA3) |
On harvested or multi-CCD parts (5900X 6+6, 5600X 6-of-8, 9900X, ...) the SMU
addresses physical core slots, with gaps where cores are fused off. On Linux the
kernel exposes each core's physical, gap-preserving core id (decoded from the APIC
ID via CPUID Fn8000_001E), so the driver derives the physical slot directly as
core id % 8 and the CCD from L3 topology -- a CO write always lands on the intended
core, with no SMU slot-probing. (Windows tools read the SMN core-disable fuse for the
same result because Windows enumerates cores contiguously; Linux gives it to us.)
All generations support PBO scalar read/write (1.0x to 10.0x) and OC mode enable/disable. SMU features require the ryzen_smu kernel module (amkillam fork) and root or appropriate sysfs permissions.
| Generation | Stress Testing | Curve Optimizer | CO Range |
|---|---|---|---|
| Zen 1 / Zen+ | Yes | No (PBO limits/scalar only) | -- |
| Zen 2 | Yes | No (PBO limits/scalar only) | -- |
| Zen 3 / 3D | Yes | Full | -30 to +30 |
| Zen 4 / 4D | Yes | Full | -50 to +30 |
| Zen 5 / 5D | Yes | Full | -60 to +10 |
| Intel | Yes | No | -- |
Curve Shaper is a Zen 5 feature that adjusts voltage across 5 frequency regions and 3 temperature points (15 tuning parameters total), stacking on top of Curve Optimizer offsets. Curve Shaper is BIOS-only -- there are no known SMU commands to read or write it at runtime, so this tool cannot interact with it. Configure Curve Shaper in your BIOS alongside CO, then use this tool to validate the combined result.
This tool imposes no artificial limits on boost clocks. A BIOS PBO Boost Override of
+200 MHz is respected; a BCLK of 105 MHz or higher (AM5) scales the effective clocks
and the tool adapts. System-state detection reads the actual max frequency from
cpufreq sysfs.