ACPI 5.0 Support In Linux: There's A Lot Left To Do
Phoronix: ACPI 5.0 Support In Linux: There's A Lot Left To Do
One of the areas where the Linux kernel is still catching up with compared to Windows is power management for some classes of hardware and with that the ACPI support. While there is some level of ACPI 5.0 support, other features are still being tackled for the Advanced Configuration and Power Interface...
What level of ACPI do I have?
For instance, running RedHat 6.3 on a ThinkPad W510, "cat /proc/acpi/info" gives "20090903". That's an obvious date stamp, but doesn't tell me if I have (most likely) ACPI 3 or ACPI 4. Or is that information in DSDT or FADT, in which case I need more software to extract it in human-readable form?
Plus, does a higher level of ACPI buy me anything, or is it just Ooooh! Shiny!
I really don't know which products/motherboards have ACPI 3 or more!
Since several years, all the motherboards are only ACPI 1.0 or 2.0 compliant.
Examples : Gigabyte GA-78LMT-S2 (AMD 760G / AM3+) => PnP 1.0a, DMI 2.0, SM BIOS 2.4, ACPI 1.0b
ASUS P8Q77-M2 (Intel Q77 / LGA1155) => AMI BIOS, PnP, DMI2.0, WfM2.0, SM BIOS 2.7, ACPI 2.0a
TYAN S8236-IL (socket G34 for Opteron 6200 Series) => Plug and Play (PnP) /PCI2.3 /WfM2.0 /SMBIOS2.3 /PXE boot / ACPI 2.0 power management /Power on mode after power recovery / User-configurable H/W monitoring
Ah, I just found a new Super Micro X9SAE-V (for Xeon E3 series) which is ACPI 1.0 / 2.0 / 3.0 / 4.0.
I could be completely wrong about this but perhaps the other versions only apply to laptops, where power management becomes a bigger deal.
Originally Posted by whitecat
While I like the idea of my desktop consuming less power while it's running, it isn't really that big of a deal for me. Anyone who is an overclocker ought to not care as much about this either. it wouldn't surprise me if at least 1/3 of Linux desktop users overclock their machines. It is unfortunate for laptop users but there are ways to script hdd power-downs and undervolt a CPU. GPUs seem to be the biggest problem in power management IMO but what aren't they struggling at?
Isn't ACPI 5.0 also a feature of Windows 8?
Most of the new stuff is to get win8 running and enumerating devices on non-x86 platforms (look for instance at the new Gpio objects).
Read the part about how to add an i2c bus in acpi. I don't know whether to laugh for a week or weep for humanity.
It's so much simpler in linux....
It does make me wonder how much power usage under linux would improve by simply implementing the missing ACPI functionality, though.