Equation 6 · Part 1 · Locality Is the Whole Game: The Memory Hierarchy and What a Kernel Does Not Read
Symbol I^*
What this part means
is the quantity selected or evaluated by the optimization written on the right.
Its job in the formula
is the quantity selected or evaluated by the optimization written on the right.
Full expression→Symbol I^*→Article meaning
The passage around this formula
with the peak arithmetic rate, I the arithmetic intensity in operations per byte, and B the achievable bandwidth at the level that dominates. The two terms cross at a ridge point = /B . Below it a kernel is memory-bound and its runtime is set by traffic; above it the kernel is compute-bound and traffic is hidden.
Learn the underlying idea
An exponent tells how a base is used in multiplication. In x³, x is the base and 3 is the exponent: x³ = x × x × x.
Open the illustrated exponents: repeated multiplication and powers guide →
See this notation across published equations →
Sources cited in the article section
- [5] Roofline: An Insightful Visual Performance Model for Floating-Point Programs and Multicore Architectures ↗
- [4] AI and Memory Wall ↗
- [1] FlashAttention: Fast and Memory-Efficient Exact Attention with IO-Awareness ↗
- [9] Data Movement Is All You Need: A Case Study on Optimizing Transformers ↗
These citations provide research context; check each source for the exact claim it supports.