I don't know what we did, but in my tests the write performance on trunk is about 3x faster than 0.11
http://mikeal.couchone.com/graphs/_design/app/_show/compareWriteReadTest/e69057a29bd6e4ac4ae0115fac018487 The left vertical column is the average response time in ms and the bottom horizontal line is the duration in seconds. This is comparing 50 writers and 200 readers using large document. I'm also going to run the test with small documents to see how big the difference is. Both are running with delayed_commits = false ; -Mikeal
