Standard ZooKeeper, standalone mode.

Connecting to localhost:2181 
Connected in 114 ms, handle is 0 
Testing latencies on server localhost:2181 using syncronous calls 
created     100 permanent znodes  in    898 ms (8.983710 ms/op 111.312589/sec) 
set         100           znodes  in    883 ms (8.832879 ms/op 113.213369/sec) 
get         100           znodes  in     23 ms (0.238380 ms/op 4194.975196/sec) 
deleted     100 permanent znodes  in    884 ms (8.844261 ms/op 113.067670/sec) 
created     100 ephemeral znodes  in    900 ms (9.000032 ms/op 111.110717/sec) 
watched     100           znodes  in     24 ms (0.244322 ms/op 4092.962255/sec) 
deleted     100 ephemeral znodes  in    875 ms (8.755250 ms/op 114.217184/sec) 
notif       100           watches in      0 ms (included in prior) 
Latency test complete 

With a RAM disk: 

Connecting to localhost:2181 
Connected in 3 ms, handle is 0 
Testing latencies on server localhost:2181 using syncronous calls 
created     100 permanent znodes  in      9 ms (0.094061 ms/op 10631.410321/sec) 
set         100           znodes  in      7 ms (0.071249 ms/op 14035.283095/sec) 
get         100           znodes  in      6 ms (0.066681 ms/op 14996.796339/sec) 
deleted     100 permanent znodes  in      7 ms (0.075529 ms/op 13240.013889/sec) 
created     100 ephemeral znodes  in      8 ms (0.084002 ms/op 11904.475917/sec) 
watched     100           znodes  in      6 ms (0.066779 ms/op 14974.843800/sec) 
deleted     100 ephemeral znodes  in      8 ms (0.088611 ms/op 11285.325297/sec) 
notif       100           watches in      0 ms (included in prior) 
Latency test complete