3 ms·
Less time spent waiting: yes. Like reading from disk: no. The max amount of out-of-order instructions is typically around 300 these days? Reading from disk t
by TomVDB 8y ago
Less time spent waiting: yes.
Like reading from disk: no.
The max amount of out-of-order instructions is typically around 300 these days?
Reading from disk takes millions of cycles.
It’s about avoid waits when reading from L1 and L2 cache and DRAM.
- zozbot123 8y agoYup, reading from disk will trigger a context switch from the OS, whether it happens explicitly or via a page fault involving virtual memory. (The closest parallel to that at the hardware level would be SMT.) As an aside, another rationale - perhaps a more paradigmatic one - for OOO involves achieving full use of super-scalar execution units on a processor core, when instructions have complex dependencies on one another.