5.9Intel® Turbo Boost Technology Thermal Considerations
Intel Turbo Boost Technology allows processor cores and integrated graphics cores to run faster than the baseline frequency. During a turbo event, the processor can exceed its TDP power for brief periods. Turbo is invoked opportunistically and automatically as long as the processor is conforming to its temperature, power delivery, and current specification limits. Thus, thermal solutions and platform cooling that are designed to less than thermal design guidance may experience thermal and performance issues since more applications will tend to run at or near the maximum power limit for significant periods of time.
5.9.1Intel® Turbo Boost Technology Power Control and Reporting
Package processor core and internal graphics core powers are self monitored and correspondingly reported out.
•With the processor turbo disabled, rolling average power over 5 seconds will not exceed the TDP rating of the part for typical applications.
•With turbo enabled (see Figure 18 on page 75)
—For the PL1: Package rolling average of the power set in POWER_LIMIT_1 (TURBO_POWER_LIMIT MSR 0610h bits [14:0]) over time window set in POWER_LIMIT_1_TIME (TURBO_POWER_LIMIT MSR 0610h bits [23:17]) must be less than or equal to the TDP package power as read from the PACKAGE_POWER_SKU MSR 0614h for typical applications. Power control is valid only when the processor is operating in turbo. PL1 lower than the package TDP is not guaranteed.
—For the PL2: Package power will be controlled to a value set in
POWER_LIMIT_2 (TURBO_POWER_LIMIT MSR 0610h bits [46:32]). Occasional brief power excursions may occur for periods of less than 10 ms over PL2.
The processor monitors its own power consumption to control turbo behavior, assuming the following:
•The power monitor is not 100% tested across all processors.
•The Power Limit 2 (PL2) control is only valid for power levels set at or above TDP and under workloads with similar activity ratios as the product TDP workload. This also assumes the processor is working within other product specifications.
•Setting power limits (PL1 or PL2) below TDP are not ensured to be followed, and are not characterized for accuracy.
•Under unknown work loads and unforeseen applications the average processor power may exceed Power Limit 1 (PL1).
•Uncharacterized workloads may exist that could result in higher turbo frequencies and power. If that were to happen, the processor Thermal Control Circuitry (TCC) would protect the processor. The TCC protection must be enabled by the platform for the product to be within specification.
An illustration of Intel Turbo Boost Technology power control is shown in the following sections and figures. Multiple controls operate simultaneously allowing for customization for multiple system thermal and power limitations. These controls provide turbo optimizations within system constraints.
Intel® Xeon® Processor |
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Datasheet – Volume 1 of 2 | June 2013 |
74 | Order No.: |