[Bug 56101] New: Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[Bug 56101] New: Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101

           Summary: Intel Core2 Duo E6600 reports max-frequency of just
                    900 MHz instead of 2.4 GHz
           Product: Power Management
           Version: 2.5
    Kernel Version: 3.8.5
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: cpufreq
        AssignedTo: cpufreq@vger.kernel.org
        ReportedBy: spam@kernelspace.de
                CC: trenn@suse.de
        Regression: No


Created an attachment (id=96971)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=96971)
Output of dmesg

I discovered that my IBM Intellistation M Pro 9229Y with its Intel
Core2 Duo E6600 is reported to clock only at a max frequency of 900.000
MHz instead of 2.4 GHz.

cpufreq-info only lists 600 and 900 MHz as hardware-supported frequencies.

The BIOS is at the latest version 1.35A, there have been no updates since 2008
(this being a rather outdated IBM workstation...)

Please see the attached output of dmesg, cpufreq-info, /proc/cpuinfo and
dmidecode for further information.

Thanks in advance

Simon

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #1 from S. Kalteis <spam@kernelspace.de>  2013-04-02 09:41:43 ---
Created an attachment (id=96981)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=96981)
Output of cpufreq-info

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #2 from S. Kalteis <spam@kernelspace.de>  2013-04-02 09:42:10 ---
Created an attachment (id=96991)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=96991)
Contents of /proc/cpuinfo

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #3 from S. Kalteis <spam@kernelspace.de>  2013-04-02 09:42:34 ---
Created an attachment (id=97001)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=97001)
Output of dmidecode

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101


Thomas Renninger <trenn@suse.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |NEEDINFO




--- Comment #4 from Thomas Renninger <trenn@suse.de>  2013-04-02 10:09:45 ---
Please provide dmesg and acpidump output as well.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #5 from S. Kalteis <spam@kernelspace.de>  2013-04-02 10:18:33 ---
Created an attachment (id=97021)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=97021)
Output of acpidump

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #6 from S. Kalteis <spam@kernelspace.de>  2013-04-02 10:20:04 ---
(In reply to comment #4)
> Please provide dmesg and acpidump output as well.

Please see attachments 96971 and 97021 above.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #7 from S. Kalteis <spam@kernelspace.de>  2013-04-05 12:54:46 ---
Hmm... this really might be related to only *reporting* wrong frequencies but
not actually *clocking* at 900 MHz.

I did a couple of tests using UnixBench 5.1.3 on kernel 3.8.5 with acpi-cpufreq
loaded (reporting a max of 900 MHz) and with Enhanced SpeedStep switched off in
BIOS settings (thus supposedly running at full clock speed of 2.4 GHz).

In both cases reported benchmark numbers are relatively close at about 830 to
880 (SpeedStep off = faster) points for single-threaded passes and 1430 to 1490
(SpeedStep on = faster) for two parallel tests.
I guess if the Core2 Duo really were throttled at 900 MHz, the numbers with the
cpufreq-driver loaded should be dramatically lower (though this is speculation
on my part).

Maybe this helps clear up things...

Thanks,

Simon

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #8 from Thomas Renninger <trenn@suse.de>  2013-04-05 13:45:16 ---
I already wrote something, but forgot to hit the apply button:

Your acpidump tool does not copy dynamically loaded SSDT tables yet.
Either make sure to take the latest one (from acpica sources afaik) or just
attach these files: /sys/firmware/acpi/tables/dynamic

-> The cpufreq info passed from BIOS to OS is in there.

You can use
cpupower monitor
tool (sources located in the kernel, depending on the distribution it might
have another name, which should get addressed by distro maintainers, there
should be a separate cpupower package on Linux distros).
This will show you the exact frequency your cores run on over a certain amount
of time (or workload if a command is appended) including boosting.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #9 from S. Kalteis <spam@kernelspace.de>  2013-04-05 14:09:28 ---
Created an attachment (id=97471)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=97471)
Contents of /sys/firmware/acpi/tables/dynamic/SSDT2

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #10 from S. Kalteis <spam@kernelspace.de>  2013-04-05 14:10:06 ---
Created an attachment (id=97481)
 --> (https://bugzilla.kernel.org/attachment.cgi?id=97481)
Contents of /sys/firmware/acpi/tables/dynamic/SSDT3

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #11 from S. Kalteis <spam@kernelspace.de>  2013-04-05 14:14:25 ---
(In reply to comment #8)
> You can use
> cpupower monitor
> tool (sources located in the kernel, depending on the distribution it might
> have another name, which should get addressed by distro maintainers, there
> should be a separate cpupower package on Linux distros).
> This will show you the exact frequency your cores run on over a certain amount
> of time (or workload if a command is appended) including boosting.

cpupower monitor (from kernel 3.8.5) exits after printing the following output:

     |Mperf               
CPU | C0   | Cx   | Freq 
   0|******|******|******
   1|******|******|******


instead of running continously, I guess.

cpupower monitor -l gives:

Monitor "Mperf" (3 states) - Might overflow after 922000000 s
C0      [T] -> Processor Core not idle
Cx      [T] -> Processor Core in an idle state
Freq    [T] -> Average Frequency (including boost) in MHz


For the acpi-tables, see attachments.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #12 from S. Kalteis <spam@kernelspace.de>  2013-04-05 14:23:50 ---
Sorry, msr.ko was not loaded. cpupower monitor still exits after one second.
Displaying e.g.

    |Mperf               
CPU | C0   | Cx   | Freq 
   0|  3.19| 96.81|  1595
   1|  1.56| 98.44|  1595


(typical Desktop tasks running)

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101





--- Comment #13 from Thomas Renninger <trenn@suse.de>  2013-04-05 14:48:44 ---
In SSDT2 the P-states show up your BIOS tells the OS which are supported
through _PSS ACPI function:
       Name (_PSS, Package (0x02)  // _PSS: Performance Supported States
        {
            Package (0x06)
            {
                0x00000384,
                0x00006978,
                0x0000000A,
                0x0000000A,
                0x0000092A,
                0x0000092A
            },

            Package (0x06)
            {
                0x00000258,
                0x000032C8,
                0x0000000A,
                0x0000000A,
                0x0000061B,
                0x0000061B
            }
        })

In ACPI spec chapter 8.4.4.2 is stated this info means:
CoreFreq, // DWordConst
Power, // DWordConst
TransitionLatency, // DWordConst
BusMasterLatency, // DWordConst
Control, // DWordConst
Status // DWordConst

Taking the first one (CoreFreq):
0x384 -> 900
0x258 -> 600
the kernel is doing everything correct (and I would have been surprised if not,
this stuff works for years).
This clearly is a BIOS bug not much can be done about (beside searching for a
related BIOS option or BIOS upgrade).

> cpupower monitor still exits after one second.
This is normal behavior, it only can monitor frequency over time, default 1
second.
C0 means core is actively processing something
Cx means the core is idle (depending which C-states are supported in deeper
                           ones)
Later CPUs cpupower monitor can detect in which C-states the CPU really was
(even the kernel thinks it triggered other states).

If properly packaged:
cpupower <subcommand> --help
should invoke the correct manpage:
man cpupower-<subcommand>(8)
in this case.
You could pass -i seconds parameter to let cpupower monitor scan the frequency
for longer.

You can do:
cat /dev/zero >/dev/null &
to utilize one core.
then try again:
cpupower monitor
if the frequency is ramped up, you are fine and the only defect is wrongly
shown CPU frequency info (through the BIOS and therefore through the kernel and
therefore with userspace tools as well).

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.

[Bug 56101] Intel Core2 Duo E6600 reports max-frequency of just 900 MHz instead of 2.4 GHz

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=56101


S. Kalteis <spam@kernelspace.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEEDINFO                    |CLOSED
         Resolution|                            |INVALID




--- Comment #14 from S. Kalteis <spam@kernelspace.de>  2013-04-05 15:17:33 ---
Ah, ok, I read the -i option as output update interval (like top -d <secs>).

Stressing one core indeed shows a frequency of 2.4 GHz. So it *is* a BIOS bug.

I guess IBM won't release a new BIOS revision for a machine that old. :-)

Thank you for your time & effort, case closed.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.