# Overclocking an intel i5 2500K

## Hammett

Hi guys, 

I recently bought an intel i5 2500K with overclocking in mind.

I chose an Asus P8P67 Pro motherboard

I have set the overclocking through Tuner AI menu in the BIOS of the system and the kernel is on "On demand" governor

My idea is having the CPU nice and cool when idle but pump all its power while heavy duty.

Although in the BIOS I set up a max freq for CPU of 4.3GHz, cpufreq-info show this:

```

cpufrequtils 007: cpufreq-info (C) Dominik Brodowski 2004-2009

Report errors and bugs to cpufreq@vger.kernel.org, please.

analyzing CPU 0:

  driver: acpi-cpufreq

  CPUs which run at the same hardware frequency: 0 1 2 3

  CPUs which need to have their frequency coordinated by software: 0

  maximum transition latency: 10.0 us.

  hardware limits: 1.60 GHz - 3.30 GHz

  available frequency steps: 3.30 GHz, 3.30 GHz, 3.20 GHz, 3.10 GHz, 3.00 GHz, 2.90 GHz, 2.80 GHz, 2.70 GHz, 2.60 GHz, 2.50 GHz, 2.40 GHz, 2.30 GHz, 2.20 GHz, 2.10 GHz, 2.00 GHz, 1.60 GHz

  available cpufreq governors: ondemand, performance

  current policy: frequency should be within 1.60 GHz and 3.30 GHz.

                  The governor "ondemand" may decide which speed to use

                  within this range.

  current CPU frequency is 1.60 GHz (asserted by call to hardware).

analyzing CPU 1:

  driver: acpi-cpufreq

  CPUs which run at the same hardware frequency: 0 1 2 3

  CPUs which need to have their frequency coordinated by software: 1

  maximum transition latency: 10.0 us.

  hardware limits: 1.60 GHz - 3.30 GHz

  available frequency steps: 3.30 GHz, 3.30 GHz, 3.20 GHz, 3.10 GHz, 3.00 GHz, 2.90 GHz, 2.80 GHz, 2.70 GHz, 2.60 GHz, 2.50 GHz, 2.40 GHz, 2.30 GHz, 2.20 GHz, 2.10 GHz, 2.00 GHz, 1.60 GHz

  available cpufreq governors: ondemand, performance

  current policy: frequency should be within 1.60 GHz and 3.30 GHz.

                  The governor "ondemand" may decide which speed to use

                  within this range.

  current CPU frequency is 1.60 GHz (asserted by call to hardware).

analyzing CPU 2:

  driver: acpi-cpufreq

  CPUs which run at the same hardware frequency: 0 1 2 3

  CPUs which need to have their frequency coordinated by software: 2

  maximum transition latency: 10.0 us.

  hardware limits: 1.60 GHz - 3.30 GHz

  available frequency steps: 3.30 GHz, 3.30 GHz, 3.20 GHz, 3.10 GHz, 3.00 GHz, 2.90 GHz, 2.80 GHz, 2.70 GHz, 2.60 GHz, 2.50 GHz, 2.40 GHz, 2.30 GHz, 2.20 GHz, 2.10 GHz, 2.00 GHz, 1.60 GHz

  available cpufreq governors: ondemand, performance

  current policy: frequency should be within 1.60 GHz and 3.30 GHz.

                  The governor "ondemand" may decide which speed to use

                  within this range.

  current CPU frequency is 1.60 GHz (asserted by call to hardware).

analyzing CPU 3:

  driver: acpi-cpufreq

  CPUs which run at the same hardware frequency: 0 1 2 3

  CPUs which need to have their frequency coordinated by software: 3

  maximum transition latency: 10.0 us.

  hardware limits: 1.60 GHz - 3.30 GHz

  available frequency steps: 3.30 GHz, 3.30 GHz, 3.20 GHz, 3.10 GHz, 3.00 GHz, 2.90 GHz, 2.80 GHz, 2.70 GHz, 2.60 GHz, 2.50 GHz, 2.40 GHz, 2.30 GHz, 2.20 GHz, 2.10 GHz, 2.00 GHz, 1.60 GHz

  available cpufreq governors: ondemand, performance

  current policy: frequency should be within 1.60 GHz and 3.30 GHz.

                  The governor "ondemand" may decide which speed to use

                  within this range.

  current CPU frequency is 1.60 GHz (asserted by call to hardware).

```

Kernel seems to not accept the overclock or not see it, the issue is that CPU stops at 3.30GHz regardless of the overclock in the BIOS.

So I don't really know what to do next. I have set both auto and manual overclocking on the MB but then cpufreq-info shows no info at all

I know this might not be the right forum and that it might suit best to post in an overclocking forum, but any light on this matter will help

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## andrewthomas

I believe you are going to have to switch to the performance governor to get the frequency above 3.3 GHz, then switch back down to the ondemand governor when you want it to scale down.

By the way, what kind of cooling system do you have that enables a 30% overclock?

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## Hammett

Hi!

I have tried to switch to performance governor while enabling Intel Speedstep to try to power down CPU while idle, but system /proc/cpuinfo only shows 3.3GHz and conky shows 3301MHz

I have found a thread on the Arch forums with the same issue I am having and, long story short, kernel is not able to see the overclocked frequency and thus only shows the standard frequency

It looks like the first 3.30Ghz is the overcloked one (the one conky reports as 3301MHz) but will not update to the current frequency

```
available frequency steps: 3.30 GHz, 3.30 GHz, 3.20 GHz, 3.10 GHz, 3.00 GHz, 2.90 GHz, 2.80 GHz, 2.70 GHz, 2.60 GHz, 2.50 GHz, 2.40 GHz, 2.30 GHz, 2.20 GHz, 2.10 GHz, 2.00 GHz, 1.60 GHz
```

Full thread: https://bbs.archlinux.org/viewtopic.php?pid=899261

And as for the cooling system, the i5 and the i7 are reported to sustain quite a lot of overclocking with the regular air cooling system. I have seen some overclocking guides to put an i7 to 4.7GHz (with liquid cooling)

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## outspoken

i'm starting to think linux is not capable of handling overclocked speedstep in the new i5/i7 p67/z68 world.

i just got my ASUS P8Z68-V Pro/GEN3 system setup with an i5 2500K overclocked to 4.5GHz and even with the latest kernels and firmwares /proc/cpuinfo, cpufreq and others still only show 3.30GHz as the maximum available option.

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## Ant P.

/proc/cpuinfo only shows what the CPU itself says it is, and overclocked CPUs usually aren't smart enough to report the real frequency. Try comparing BogoMIPS values at boot.

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