A recent change to Jenkins led to an unexpected throughput drop in the wtperf evict jobs in Jenkins. The regression was introduced by: http://build.wiredtiger.com:8080/job/wiredtiger-perf-evict/495/
That is adding in more eviction worker threads to the wtperf configuration files. Which was related to
Testing with more eviction worker threads is more interesting that testing a single eviction worker - so it is worthwhile understanding the source of the difference.