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How to increase arithmetic intensity?
One way to increase the arithmetic intensity is to consider gauge field compression to reduce memory traffic (reduce the size of G), and using the essentially free FLOP-s provided by the node to perform decompression before use.
What is arithmetic intensity?
Arithmetic intensity is a measure of floating-point operations (FLOPs) performed by a given code (or code section) relative to the amount of memory accesses (Bytes) that are required to support those operations. It is most often defined as a FLOP per Byte ratio (F/B).
How to find arithmetic intensity?
Arithmetic Intensity is the ratio of total floating-point operations to total data movement (bytes). A BLAS-1 vector-vector increment ( x[i]+=y[i] ) would have a very low arithmetic intensity of 0.0417 (N FLOPS / 24N Bytes) and would be independent of the vector size.
What is the main idea behind the roofline model in performance analysis of multicore systems?
The Roofline model is an intuitive visual performance model used to provide performance estimates of a given compute kernel or application running on multi-core, many-core, or accelerator processor architectures, by showing inherent hardware limitations, and potential benefit and priority of optimizations.
What is computational intensity?
First recall the definition: The computational intensity of an algorithm is q = f / m, where f is # of basic operations (e.g. floating-‐point adds and multiplies) and m is # of words moved between fast and slow memory. Thus, the statement in the inner loop always moves one word, B(k,j), from slow to fast memory.
What is operational intensity?
Operational intensity I(n) = W(n)/Q(n) = number of flops (cost) number of bytes transferred. between memory and cache.
What is roofline performance model?
Roofline is a visually intuitive performance model created by Samuel Williams that is used to bound the performance of various numerical methods and operations running on multicore, manycore, or accelerator processor architectures.
What is the roofline analysis and why is it useful?
Roofline analysis helps in determining the gap between an application and the potential of a computer. That ends up guiding our optimization work, and occasionally inspiring algorithm changes.
What is roofline analysis?
Roofline analysis helps in determining the gap between an application and the potential of a computer. The more intense a computation is (as the graph moves to the right), the more likely we become limited by the machine’s compute capabilities rather than its data capabilities.