I have render multiple frames simultaneously enabled, and am using 3 cores with 2 gb each.
So yesterday, I noticed that my render speeds were slowing down dramatically, almost as if it were using only one core. Curious, I took a look at my CPU performance. What I saw was this:
This is definitely different from my usual utilization which is a smooth line near 80%. I checked and my CPU isn't overheating, and performance wise my system is not experiencing any lag. What's puzzling is that when I rendered the same sequence a couple of days ago, it rendered with normal speeds.
Your disk speeds seem about maxed, which may be a part of it. Same with RAM. Have you restarted and retried? I just had an exchange yesterday about AE's inefficiencies and can tell you from my own experience that un/known variables can alter a render from one day to the next.
Agree with OzzyofLA - lots of disk activity - not necessarily AE, but could be another system process...