Hi, does anyone experience the same and knows the answer?

I have two datasets on different zpools. Both datasets are encrypted. When I copy from non-ZFS volume (or non-encrypted ZFS dataset) to an encrypted dataset then I don't observe any speed degradatation. Also, CPU utilisation on i5-11500 is less than 25%.

However, when I try to copy from one encrypted dataset to another encrypted dataset (on different pools) then my speed just sucks. The average transfer is less than 50MBps (while normally it's ~1000MBps). Also, CPU utilisations goes 50% average and spikes to 75%. CPU is probably OK (still, I wonder why ZFS doesn't make use of the AES instruction set). But the low speed is what bugs me most!

The degraded speed looks very similar to what I get if I intentionally do "zfs set sync=disabled" on any of my datasets. All of my zvols are on SSDs.

PS. both encrypted datasets are in the respective raidz1 if that matters.