AMD Cool 'n' Quiet, Turbo Core Impact On Linux

While Turbo Core did not help the Unigine Tropics frame-rate, the CPU was left running much warmer.

In addition, the overall system power consumption was up.

In this brief look at Cool 'n' Quiet and Turbo Core 2.0 for AMD's latest-generation Bulldozer hardware under Linux, there is a few findings:

- Turbo Core 2.0 is beneficial under Linux. However, it is mostly beneficial for single-threaded tests or workloads that do not stress all available CPU cores/modules. When all cores/modules are under load, there was normally no difference in performance. Obviously, due to running at higher frequencies, the system power consumption and CPU temperature do noticeably rise with this feature enabled.

- Cool 'n' Quiet is good for dropping the CPU clock speeds and voltage when idling or with minimal load, which lower the operating temperature and system power consumption. When the FX-8150 is being stressed, having Cool 'n' Quiet enabled was not detrimental to the system's performance.

- The exposed "CPU power consumption" on Bulldozer CPUs and shown via the "fam15h_power" Linux hwmon driver is useless. Regardless of the features being enabled or what tests were run, this estimated power reading was mostly showing the same (125W TDP) value.

There is more data on OpenBenchmarking.org.