Virtual Labs

MOESI Cache Coherence Protocol

After completing the MOESI simulation, which state transition occurs when a processor writes to a cache line in Exclusive state?

a: Exclusive to Shared Explanation

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b: Exclusive to Invalid Explanation

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c: Exclusive to Modified Explanation

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d: Exclusive to Owned Explanation

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In the MOESI simulation, what happens to other processors' cache lines when one processor performs BusRdX operation?

a: They transition to Shared state Explanation

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b: They transition to Exclusive state Explanation

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c: They transition to Invalid state Explanation

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d: They remain unchanged Explanation

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Based on your simulation experience, which MOESI state requires write-back to memory when the cache line is evicted?

a: Shared and Invalid only Explanation

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b: Exclusive and Shared only Explanation

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c: Modified and Owned only Explanation

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d: All states require write-back Explanation

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During the simulation, when does cache-to-cache transfer occur in the MOESI protocol?

a: When any processor reads shared data Explanation

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b: When a processor reads data from another processor in Modified or Owned state Explanation

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c: When a processor writes to Invalid cache line Explanation

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d: When processors synchronize their clocks Explanation

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From your simulation observations, what is the main advantage of the Owned state over immediately writing back to memory?

a: It eliminates all future cache misses Explanation

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b: It reduces memory bandwidth usage and allows data sharing Explanation

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c: It prevents other processors from accessing the data Explanation

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d: It automatically updates all shared copies Explanation

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In your simulation, when a processor in Shared state wants to write data, which bus operation is generated?

a: BusRd to read the latest data Explanation

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b: BusRdX to get exclusive access Explanation

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c: BusUpgr to invalidate other shared copies Explanation

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d: BusFlush to write current data Explanation

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Based on your simulation experience, which scenario would generate the most bus traffic in a MOESI system?

a: Multiple processors reading the same data repeatedly Explanation

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b: A single processor repeatedly writing to private data Explanation

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c: Multiple processors alternately writing to the same memory location Explanation

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d: Multiple processors reading different memory locations Explanation

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In a complex simulation scenario, if processor P0 has data in Owned state and processor P1 performs a write to the same address, what is the sequence of state transitions?

a: P0: Owned→Shared, P1: Invalid→Modified Explanation

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b: P0: Owned→Invalid, P1: Invalid→Modified Explanation

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c: P0: Owned→Modified, P1: Invalid→Shared Explanation

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d: P0: Owned→Exclusive, P1: Invalid→Invalid Explanation

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After running multiple simulation scenarios, which statement best describes the scalability characteristics of the MOESI protocol?

a: Performance degrades linearly with the number of processors Explanation

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b: Bus traffic increases exponentially with sharing patterns Explanation

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c: The protocol maintains good performance for moderate sharing with cache-to-cache transfers Explanation

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d: All processors must synchronize on every memory operation Explanation

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