kernel-packages team mailing list archive

[Launchpad Bug Tracker <1396291@xxxxxxxxxxxxxxxxxx>]

You have been subscribed to a public bug:

I have an Acer Aspire 5720 and it is set up to dual boot Vista and
ubuntu 14.04 LTS. From new the laptop came with an Intel T7300 2.00 Ghz
CPU and 1 GB DDR2 RAM. A few weeks ago I upgraded to 4 GB RAM, which
works perfectly, and a few days ago I upgraded to an Intel T9300 2.5 Ghz
CPU.

The BIOS (up to date), Vista and ubuntu all recognise the CPU correctly
as:

"Intel(R) Core(TM)2 Duo CPU T9300 @ 2.50 GHz".

Vista allows the CPU to run correctly at up to 2.5 Ghz and will step the
CPU speed lower when not needed, depending on which power settings are
chosen.

The problem is that ubuntu will only allow the CPU to run at a fixed
frequency of 2.4 Ghz, which is incorrect as it's a 2.5Ghz CPU, and there
is no stepping to lower the CPU frequency when max frequency is not
needed.

"cpupower frequency-info" in a terminal returns:

analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 2.40 GHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.40 GHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 2.40 GHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 2.40 GHz.
cpufreq stats: 2.40 GHz:10.47%, 2.40 GHz:89.53% (12799)
boost state support:
Supported: yes
Active: yes 

I have tried using ondemand, performance and powersave - nothing makes
any difference. I have also installed CPU Frequency Scaling Indicator
(which shows only 2.4 Ghz and 2.4 Ghz (turbo mode) as available
frequencies) and I have also tried TLP but nothing makes any difference.

According to this website:

http://www.phoronix.com/scan.php?page=article&item=mobile_penryn&num=3

the T9300 CPU should have the following frequency steps:

2.50 GHz, 2.00 GHz, 1.60 GHz, 1.20 GHz and 800 MHz.

I have spent days trawling the internet for a solution but to no avail.
Hence filing this bug report in the hope a solution might be found.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: bot-comment cpu frequency
-- 
Maximum CPU frequency incorrect and there is no CPU scaling
https://bugs.launchpad.net/bugs/1396291
You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu.