Intel Core i5-2467m Turbo Boost – Why It Isn’t Activating and How to Fix

cpucpu usagewindows 7

I have a Samsung Series 5 laptop with an Intel Core i5-2467m process @ 1.6Ghz. The processor supports Intel Turbo Boost up to 2.30 Ghz according to the specifications. The i5-2467m is a dual-core process with HyperThreading, so there is a total of four (4) virtual cores in Windows 7 SP1.

I've installed the Intel Turbo Boost Technology Monitor v2.6 to monitor if Turbo Boost is enabled, and set it to "Always On Top."

I followed this process to max out the CPU:

  1. Open (4x) PowerShell instances
  2. Set each instance's affinity to a distinct CPU vCore
  3. Ran this code in each instance: while (1 -eq 1) { }

Unfortunately, after maxing out all 4 cores, my laptop got hot, but Turbo Boost never kicked in.

Any ideas on how to ensure that I'm getting the 2.3Ghz Turbo Boost capability of my laptop?

Best Answer

Turbo boost is supposed to boost the CPU speed within thermal limits, if only one core is in use but the thermal limit is not met then Turbo Boost will boost the CPU speed for short periods.

By trying to load all 4 cores you are most likely surpassing the thermal limit and thus preventing it from activating.

As per Wikipedia:

The increased clock rate is limited by the processor's power, current and thermal limits, as well as the number of cores currently in use and the maximum frequency of the active cores. When workload on the processor calls for faster performance, and the processor is below its limits, the processor's clock will increase the operating frequency in regular increments as required to meet demand. Frequency increases occur in increments of 133 MHz for Nehalem microarchitecture processors and 100 MHz for Sandy Bridge microarchitecture processors. When any of the electrical or thermal limits are reached, the operating frequency automatically decreases in decrements of 133 MHz/100 MHz until the processor is again operating within its design limits.

That Wikipedia page also shows some examples of Turbo Boost functioning and as more cores are in use the boosted speed is lower.

Try running only 1 worker thread and keeping your laptop as cool as you can, then Turbo Boost should activate.

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