摘要:
A method and apparatus for power mode transition in a multi-thread processor. A first indication is issued, including a first identifier associated with a first logical processor in a processor, that the first logical processor has entered a power mode. A second indication is issued, including a second identifier associated with a second logical processor in the processor, that the second logical processor has entered the power mode. The indications may be, for example, stop grant acknowledge special bus cycles indicating that the logical processors have entered a stop grant mode. The processor may be transitioned to a sleep mode when both the first and second indications have been issued.
摘要:
An apparatus and method for dynamically adjusting the power/performance characteristics of a memory subsystem. Since the memory subsystem access requirements are heavily dependent on the application being executed, static methods of enabling or disabling the individual memory system components (as are used in prior art) are less than optimal from a power consumption perspective. By dynamically tracking the behavior of the memory subsystem, the invention predicts the probability that the next event will have certain characteristics, such as whether it will result in a memory cycle that requires the attention of a cache memory, whether that memory cycle will result in a cache memory hit, and whether a DRAM page hit in main memory will occur if the requested data is not in one of the levels of cache memory. Based on these probabilities, the invention dynamically enables or disables components of the subsystem. By intelligently adjusting the state of these components, significant power savings are achieved without degradation in performance.