I recently went through the process of encrypting all the disks in my array. Is it typical to expect a dramatic decrease in performance? I understand that this could happen because of the extra work required but I was under the impression, and based of other Unraid experiences I found on the internet, that with sufficient CPU it should not have that great of an impact. I cannot write faster than 60MB/s, prior to encryption I was usually over 100MB/s. My server is a Dell R530 with 2x Xeon E5-2630 v3. That proc has the features that should be able to handle encryption sufficiently. I even tried messing around with disk tunables to see if I could squeeze more out of it, nothing gets it past 60.

 

Any insight would be greatly appreciated. Thanks in advance.

You may have been fooled by caching. My dual Xeon 2670 with 96gb ram will show wildly different write speeds depending on ram available. The first 50-75gb is being written to the ram cache and happens at a much faster speed.

Also a write to a non array drive will happen significantly faster than an array drive where parity needs to be calculated.

Overall I can't say I notice my encrypted drives being any slower to write than my non encrypted drives. There must be some slow down but on my system it isn't noticed.

Sent from my chisel, carved into granite

I have 32GB of RAM and have watched the values in Netdata monitor docker, I have never seen more than 1-1.5GB being written to RAM. The big difference is when using the unbalance tool to move files between disks. Before encryption it would easily be above 80MB/s for the duration of the move, now I am lucky if it gets to 50MB/s.