ASUS P9X79 WS
More actions
| Reported | |
| CPU | Intel LGA2011 (X79) |
|---|---|
| Runs on | Bare metal |
| OS / driver | Ubuntu (version not given) |
| ReBAR / BAR1 | Unlock works after the MMIOH change; BAR1 size not reported |
| Settings that mattered | Above 4G Decoding available in the BIOS; the 64-bit MMIO (MMIOH) window was too small until kernel parameters were changed (exact parameters not posted) |
| Tested by | @fdelfini |
| Source | Discord message |
| Confirmations | None yet. |
Fernando Delfini could not unlock a card on his X79 WS board at first and asked whether the platform's MMIO limits were the cause. Source: @fdelfini, 2026-10-19
What was suggested
GlobalApathy guessed Above 4G Decoding and Resizable BAR might be missing or hidden on that BIOS. His AI assistant's explanation: the P9X79 WS BIOS allocates a small window (typically 2 to 16 GB) for 64-bit devices above 4 GB, so a 64 GB BAR request fails, and the hidden MMIOH Base and Size would need a BIOS edit with AMIBCP 4.55 rather than a setup_var toggle. Theory Source: @globalapathy, 2026-10-19
Source: @globalapathy, 2026-10-19
What worked
Fernando's board already had Above 4G Decoding. His assistant "changed some ubuntu parameters and unlocked mmioh size", and it then worked. Source: @fdelfini, 2026-10-19
Source: @fdelfini, 2026-10-19 The exact kernel parameters were not posted; pci=realloc is the usual candidate (see Server BIOS setup case C). If you get this board working, post the parameters.