I decided to revert the HP bios back to F.06, and now - to my surprise, on boot, I get an extra SSDT! (The CpuPm one). [17179569.184000] ACPI: RSDP (v000 HP ) @ 0x000f7d70 [17179569.184000] ACPI: RSDT (v001 HP 30AA 0x28040620 HP 0x00000001) @ 0x3f7e5684 [17179569.184000] ACPI: FADT (v002 HP 30AA 0x00000002 HP 0x00000001) @ 0x3f7e5600 [17179569.184000] ACPI: MADT (v001 HP 30AA 0x00000001 HP 0x00000001) @ 0x3f7e56c0 [17179569.184000] ACPI: MCFG (v001 HP 30AA 0x00000001 HP 0x00000001) @ 0x3f7e5728 [17179569.184000] ACPI: TCPA (v002 HP 30AA 0x00000001 HP 0x00000001) @ 0x3f7e5764 [17179569.184000] ACPI: SSDT (v001 HP HPQSAT 0x00000001 MSFT 0x0100000e) @ 0x3f7f4af8 [17179569.184000] ACPI: SSDT (v001 HP CpuPm 0x00003000 INTL 0x20050624) @ 0x3f7f5327 [17179569.184000] ACPI: DSDT (v001 HP nc6340 0x00010000 MSFT 0x0100000e) @ 0x00000000 The CpuPm SSDT table contains _PDC and _OSC methods, and generally looks useful. Still, linux doesn't load either speedstep-centrino, or acpi-speedstep. I'll poke some more, but it looks promising. I wounder why the BIOS F.08 doesn't have the CpuPm SSDT? It appeared to flash correctly when I first installed it. Perhaps even booting windows (to downgrade to F.06) had some effect on the bios to bring back the SSDT? Perhaps it is only in the F.06. Does anyone have any contacts with HP who might shed any light on this? Regards Peter Clifton - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html