[godi]

Running your benchmark I get 11216 increments per second

Running the redis-benchmark from (http://redis.googlecode.com/files/redis-2.0.4.tar.gz) with 50 parallel clients 37800 requests per second

I would like to see the numbers for 50 clients to mongo doing the same.

[antirez]

interesting but 37800 is low too, either not Linux or is a Virtual Machine :) That's what I get in my desktop system with Linux (Xeon E5520 2.27 Ghz):

INCR: 126743.98 requests per second