advanced · perf
Reading the Counters
A loop shows low IPC, a low L1 miss rate, a high last-level cache miss rate and memory bandwidth near the platform maximum. Is it compute-bound or memory-bound, and what would you do?
Practical scenario
An analytics kernel is being optimised. Someone has proposed doubling the instance size on the basis that CPU utilisation reads 100%.
What it tests
- • Whether the candidate reasons from evidence rather than intuition
- • Understanding that low IPC means stalls, not necessarily heavy computation
- • Knowledge that bandwidth saturation changes which fixes can work