Why would you not have to fsync? The fsync is a memory barrier that is just as useful with octane to ensure integrity.
Do you mean the latency of ensuring fsync safety is lower?
Do you mean the latency of ensuring fsync safety is lower?
No they don't. A fence only imposes ordering. It's instant. It can increase the chance of a stall when it forbids certain optimizations, but it won't cause a stall by itself.
CLWB is a small flush, but as tanelpoder explained the more recent CPUs did not need CLWB.