I overstated the CPU regression in MySQL 5.7
My series of posts on the low-concurrency CPU regression greatly overstated the regression from MySQL 5.6 to 5.7. Most of the regression was from the use of SSL which is enabled by default starting with 5.7. My results for 5.7 and 8.0 were slower courtesy of SSL while earlier versions of MySQL were not using SSL. I repeated tests for 5.7 and 8.0 with SSL disabled (ssl=0 in my.cnf) and now show a QPS loss of 10% to 20% from 5.6 to 5.7/8.0. There is still a large regression from MySQL 5.0 to 8.0 and I will continue to document that and expect to help reduce it. I expect 86215 to be closed as not a bug. tl;dr for in-memory sysbench at low concurrency MySQL 5.7 and 8.0 lose 10% to 20% of QPS versus 5.6 for tests not dominated by range scans InnoDB range scans were made faster starting in MySQL 5.7 In the worst case, MySQL 5.0 gets more than 2X the QPS versus 5.7 and 8.0. The largest QPS regression occurs between MySQL 5.5 and 5.6. Why I should have noticed earlier in the p