Interview Method and Worked Scenarios · arch

Computer Architecture · All levels

Strong whiteboard answers follow one method. Name the workload, draw the path, size with arithmetic, then validate with counters.

Five-step whiteboard flow: workload, targets, hierarchy, sizing, validation.

The five whiteboard steps run left to right, from workload class to PMU validation.

Lesson	What it covers
Framework	The five whiteboard steps with sizing arithmetic.
Cache storm	A doubled L2 MPKI traced to conflict misses, with a worked fix.
NoC deadlock	Overlapping DMA and coherent traffic, fixed with classes and QoS.
Accelerator starvation	A slow NPU split into compute, byte and overhead time, then tiled.
Coherency storm	False-shared counters flooding the fabric, proved and padded.
Validation and close	PMU validation, PPA tradeoffs, traps and the closing statement.

Check yourself An interviewer asks for a cache hierarchy for a burst-driven mobile SoC. What is the first sentence?

Name the workload class and the target metric, for example sustained IPC under a power cap. Mechanism comes after the target is stated.