The following measurements were taken with a Lenovo Thinkpad W500 with 8Gb ram & running Windows 7 SP1+fixes. The CPU is a 2.5 Ghz core duo.
Whilst not intending to do a thorough controlled test, I thought it would be interesting to see what the effect of Symantec PGP encryption might be on I/O performance
Here’s my SSD before encryption
And here’s the same afterwards
Write speed has roughly been quartered whilst read speed is a little over half
Given this is an SSD the overall throughput is still decent, though this came with a significant increase in CPU – in fact this is now the limiting factor it seems, with the “System” (ie kernel) showing maxed out CPU whilst previously this CPU wasn’t noticeably high
With the hard drive the before measurements were :
Pretty consistent and average for a hard drive. Now adding encryption
Nowhere near such a bad effect – less consistency, but due to the lower data rates the cpu load was lower, and not so close to being maxed out.
This was all done on an idle machine – so the biggest impact will be heavy UI when the system is busy. I expect bootup to be quite a bit slower for this reason