Modeling and Analysis of Dual Block Multithreading

Instruction level multithreading is a technique for tolerating long– latency operations (e.g., cache misses) by switching the processor to another thread instead of waiting for the completion of a lengthy operation. In block mul- tithreading, context switching occurs for each initiated long–latency operation. However, processor cycles during pipeline stalls as well as during context switch- ing are not used in typical block multithreading, reducing the performance of a processor. Dual block multithreading introduces a second active thread which is used for instruction issuing whenever the original (main) thread becomes in- active. Dual block multithreading can be regarded as a simple and specialized case of simultaneous multithreading when two (simultaneous) threads are used to issue instructions for a single pipeline. The paper develops a simple timed Petri net model of a dual block multithreading and uses this model to estimate the performance improvements of the proposed dual block multithreading

Enhanced interleaved multithreaded multiprocessors and their performance analysis

In interleaved multithreading, the thread changes in each processor cycle, consecutive instructions are issued from different threads, and no data dependencies can stall the pipeline. Enhanced interleaved multithreading maintains a number of additional threads which are used to replace an active thread when it initiates a long-latency operation. Instruction issuing slots, which are lost in pure interleaved multithreading are thus used by instructions from the new thread. The paper studies performance improvements due to enhanced multithreading by analyzing a timed Petri net model of an enhanced multithreaded architecture at the instruction execution level

Principles of Computer Architecture

Last week, Control Data ... announced the 6600 system. I understand that in the laboratory developing the system there are only 34 people including the janitor. Of these, 14 are engineers and 4 are programmers... Contrasting this modest effort with our vast development activities, I fail to understand why we have lost our industry leadership position by letting someone else offer the world’s most powerful computer – Thomas Watson Jr., IBM CEO, August 1963 It seems like Mr. Watson has answered his own question – Seymour Cra